Good points.
I think it's just somewhat contrived writing at this point - probably with both characters. I thought the scene a week or two ago when Mohinder called up HRG freaking out about the company wanting him to inject Monica with the virus, and HRG telling him to just do it, was a little over the top: I thought it made Mohinder look stupid for calling up HRG asking for help (what's HRG supposed to do, hold his hand the entire time? rush back from the Ukraine?), and HRG look stupid for simply suggesting Mohinder inject her, when he could have said something less harsh, like 'look, Mohinder, you'll have to improvise - pretend to inject her, talk Bob out of it, whatever - I can't help you.'
And now this week with Mohinder accusing HRG of seeing him as expendable, and HRG - instead of allaying that fear - responds with 'I'm protecting my family!' (which is basically a 'yes, you are expendable').
I really can't stand writing that makes characters act ridiculously in order to get a plot point accomplished (ie Mohinder potentially shooting HRG).