I just read a great article on this very topic on Bleacher Report. Basically it said that the Steelers organization needs to come out and say whether he was fired or retired and who made the call. They say this because Arians, who never did interviews during his time as offensive coordinator is now talking to anyone who will listen to him. He is coming off as VERY bitter. And if this was a decision from Rooney as reports indicated that went against Tomlin's wishes, Tomlin may be bitter and Roethlisberger is definitely bitter (which is HUGE considering they need him to restructure his deal). With the truth in the open, these things can be moved past but so long as everyone is whispering about them, they will continue to fester.
Here's a link to the
article. It's a great read.