I think the penalties applied to Grosjean got a bit mish mashed.
On the whole he drove pretty well all weekend, I was fearing carnage at the start where he was being squeezed pretty assertively by Vettel but for once he kept it altogether.
His move on Button was clumsy, there's no other way to describe it. He perhaps should have been told to hand the position back given that following the contact he had to cut the chicane, that would have been the most appropriate penalty. However given that Button was immediately also overtaken by Alonso and then pitted, that wasn't really practical and so a drive thru penalty would have been appropriate, which was effectively
(and rather pointlessly) applied retrospectively after the race which didn't affect the end result. They may as well have reprimanded him instead. But going by the scope of his previous, that incident was really insignificant anyway and Button didn't really lose out much by it if at all.
His move on Massa, was brilliant quite frankly. However the move
was completed by taking all four wheels across the white line which defines the boundaries of the race track and so he
did overtake by going off the track. He should have been told to give the position back. A drive thru was rather harsh.
I think he has grounds for feeling frustrated, because he ought to have been challenging for the win.