Okay, here's how I think it breaks down:
As confirmed by Andrew Kreisberg, Zoom is Hunter Zolomon, a.k.a "Jay Garrick," meaning the person Team Flash has known as Jay since this season's first episode has been manipulating them the whole time.
The Jay Garrick who was killed by Zoom? That, I believe, was Hunter Zolomon of Earth-1, who's been in cahoots with Zoom the whole time and also pretended to be Jay Garrick whenever necessary. Such as when the STAR labsters tested Jay to see if he had traces of the Speed Force to back up his story about having lost his powers it to Zoom. Or when "Jay" showed Caitlin his Earth-1 counterpart at the park bench. Or whenever he was injected with Velocity-6, 7, 8, and 9. To paraphrase a certain Christopher Nolan movie, the trick is where Zoom and Earth-1 Hunter would swap.
However, we also know that there is a real Jay Garrick who is The Flash on Earth-2 as confirmed by Harry and the flashback on Earth-2 in which Harry unveiled the metahuman detector. Moreover, Earth-2 Jay had the yellow lightning Speed Force effect just like Barry does, and whenever "Jay" took one of the Velocity serums, he also had the yellow lightning Speed Force effect. Therefore, Jay Garrick and Hunter Zolomon must share the same face.
Which leads to the theory that the real Jay Garrick is also the man in the iron mask. And not just because he taps out "J-A-Y" or that careful examination of him shows he has a similar traits to the actor who plays "Jay"/Zoom, but also because Zoom has him in a similar cage like he did Barry, which seems designed to hold speedsters.
So either, I think, we're dealing with one of two options:
a. Jay Garrick and Hunter Zolomon being identical twins on Earth-2 but on Earth-1. Or
b. When Jay was hit by his Earth's particle accelerator explosion, it not only gave him super speed, it split his personality a la Jekyll and Hyde. Remember,
Jay didn't get his speed powers the same way Barry did; Barry was struck by lightning and flew into some chemicals when the accelerator exploded, while Jay was experimenting with Heavy Water when the accelerator on his earth exploded. The reason Jay wasn't able to catch Zoom is because he was literally chasing himself. Once he discovered the truth, Jay's injected himself with Velocity-6 in an attempt to "kill" Zoom, but instead it's reaction to the Speed Force made them physically two separate people. Which would also explain why "Jay" warned Barry not to use Velocity-6 because he knew the effect it would have on those who already have access to the Speed Force. This would also explain why Zoom is attempting to absorb the Flash's speed and is dying: because having separated himself from Jay, he's physically unstable, and the Speed Force is the only thing literally holding him together.
I believe your the closet to it next to my self and a few others.
and what you said about the meta human detection scanner is also a good point. Notice that (fake Jay) that's been claiming to have been jay to the star labs doesn't have a meta human detector?
ok let;s look at the details when he came and Barry locked him up
the star labs team said they tested him. but couldn't prove he was a speedster. then he said he lost his power being put through the breach.
after the star labs decided to give him the benefit of the doubt cause some of what he said with sand demon was around was accurate. they let him out he taught barry the lighting bolt trick which he him self wasn't ever able to pull off. and it was an ability though cool was overly lethal . (sorta well it's more then this , it is suspicious )
and they found that jay's powers were connected to him, he has to have that war helmet of his, which has wings . that may have been the reason they had at starlabs all along due to what Eobard had Barry do with a trip to the past for Barry to save his mom.
so it looks the reason he lost his power was due to the helment. but he never got his powers back that way when the helmets returned.
and he said he lost his powers coming here. which made some of the fan base think speedster's loose their power coming to a new earth.
But weirdly some of the audience thought you had to be a speedster to be able traverse the breach's.
but there's more , since the events of earth 2 wells came o earth one Jay and him went at it a bit verbally. Jay in Jay jona Jameson and wolverine style manner of complaint saying not to trust earth well's. After earth 2 Dr.wells saved Barry by freezing parts of king shark and patty her first meta human arrest.
Jay disappeared mostly over his fit over the star labs team also trusting earth 2 wells along with Jay himself . which jay didn't like. to where though?
this is after the dr. light linda park event
after that I've have seen others discussed this week there must be others on earth 2 that must have known Jay in his normal life , when he's not the flash. Like co-workers or family.
Sadly Jay himself hasn't said he has family to the starlabs team he has said he is a scientist and he does know science. also he said he was testing water samples when the accelerator even of earth 2 happened and he got his powers.
after that with dr.light and Linda Park event. Barry faced off with zoom showing that he can have his own powers work in the earth one reality. which threw out that idea speedster from earth 2 loose their powers by coming earth one and staying here. just like when earth 2 D.r. well's came and save Barry killed the idea that only speedster,or people traveling through the breach's have to have speedster with them cause the speedster has to be using their powers going through the breach. but Earth 2 Dr. wells didn't need such a thing. so two idea's are dead about speedster losing their power going through the breachs between reality's of earth 1 - 2 and you can only be a speedster to travel through the breach's.
when Jay explained his story that he was fight zoom for 2 years'. he then stated Zoom took his powers.
but he wasn't sure how ?and then he was sent earth one , as he claim the second time around .
now after dr. wells started to work on the velocity serums they decided to call Jay and he went nuts again with his don't trust earth 2 dr .well's rant . and made it feel like earth 2 drwell 's created the first serum the first time and pushed it to Jay. but this was the first time earth 2 Dr.wells has attempted to make the serums and he's more of a tech genius then a geneticist or biologist, which is why Caitlin was helping him .
jay continued his blow out and stormed off to where ever he lives on earth one currently. Earth2 dr.well's says he has to run errands for them to make a better plan. after that he catch's patty's attention (something that should have happened to Malcolm merlyn in season 3 with his insane asinine strolls through star city Repeated visits to thea in the club)
Patty fallowed earth 2 dr. well's to star labs and shoot him the only person that can save earth 2 dr. wells is Jay via the viscosity 6 serum Jay's so against and overly project his anger on earth 2dr. wells for it. he uses' save 's earth 2 dr. well's and still does his don't trust wells thing again and leave's in huff.
Jay get's called back again cause Caitlin has been working on other versions of the serum and want's to find his earth one counter part, to look at that one DNA and see if they can restore earth 2 jay this way. jay say's he has something to show her.
he take's her to the park and we see his count part and he say's the reason he was hard to find was this one on earth was adopted by the zolomons and his first and last name were changesd and his name now hunter Zolomon and to not bother cause thiscounter part supposedly was never mutated DNA wise.
Again I have to point to the meta human scanner. the only one from earth 2 with the device was dr.wells. but every one else from earth 2 has one, with the exception of Jay who claims to be from there.
How did he test for earth one Hunter zolomons DNA? other normal doctor's probably don't have it in their file.
And it would mean he'd have had to approach hunter him self but he said for Caitlin not to bother cause hunter doesn't have the meta Gene. but how did Jay him self who through out this season we never seen him with a meta human scanner know Hunter Zolomon of earth 1 doesn't have the meta human Gene?
The only other way would be via a blood sample like when Barry took samples (with out their permission) from both Hewitt and Jackson to help save professor stein.
Jay him can't do what Barry did cause his powers are off. After he told Caitlin that the reason lost his powers after two false claim's that he lost his powers coming through the breach and saying Zoom stole fit from him befor breach , after saying it was when Jay came through the breach .
and he told her that day it was cause of the velocity 6 serum . and then he saying not to speak to earth one zolomon cause he doesn't have the meta gene for the cure.
Ok Jay or should I say (Fake jay). . how do you know absolutely for sure that hunter Zolomon of earth one doesn't have the meta Gene with out the meta human scanner which we've never seen on you once?
And also with out a blood sample? if you have a blood sample where is it? why are you so insistent earth one zolomon doesn't have the meta gene ? you have to have ether of those things.
some how I doubt he got close enough to hunter without hunter noticing (fake) Jay who didn't want Caitlin in the park to speak to hunter, "now that he was in front of her in the park .
she could have had Jay hide, if that was an issue. But he said hunter doesn't have the meta gene. how does jay know this? no device no blood sample just Jay (I'm still calling him fake) speaking long haul that he should be the only every one listens to alone .
all after three conflicting descriptions on how Jay(fake Jay) him self lost his powers , two of which were lies before the truththat same day he showed her hunter zolomon. but he said not to approach the latter. cause he was sure the metagene isn't in earth 1 hunter zolomon DNA.
But Jay(fake Jay) never explains how he knows it's not in earth one hunter Zolomon Gene's?
there's also that weirdness with how Geo mancer found him in labs after he told the other he needed to rest. Geo mancer attacks and the only thing significantly damaged is the speed cannon At star labs which Jay spent all day supposedly fixing before his second show down with Geo mancer before he was tired out.
ok one other thing , when jay did his blow up with velocity 6 ddiscovery , earth 2 dr.well said and he only said it once that jay (fake jay)is hiding something him self and jay stories about how he lost his speed and then saying not to approach earth one hunter zolomon, " he doesn't have the meta gene."
You lied with the power loss then there no evidence about the meta Gene in hunter zolomon other then your word.
then Andrew Kresberg said 3 time's that the jay that had been with the star Labs crew was misleading them all with half truths and is posing as Jay.
