When Massa was preparing to brake Schumacher was on the right side of the track and there was room to his left, that situation changed very quickly when Schumacher moved left. In a way its similar to Anthony Davidson's Corvette incident at Le Mans, the driver had no time to react to the changing sitatuion caused by a driver acting unpredictably and agressively ahead.
Massa can't predict exactly when Schumacher is going to brake, especially when Schumacher was struggling with handling and so probrably had to brake quite a bit earlier than most other drivers.
Its generally considered bad to move about in braking zones when you have a following car, and incidents such as this one are good examples why. Massa may not have had any overlap but Schumacher left him with nowhere to go. Massa wasn't trying to put a passing move on Schumacher, Schumi braked earlier, probrably because he was struggling with the cars handling yet again.
Of course because Schumacher is the driver in question it can't possibly be his fault. People have such warped ideas of what and what isn't acceptable in racing.
The penalty was for being late, it could be quite easy for a driver to run out of fuel and still not be late, and it could be just as easy for a driver to be late having not run out of fuel.
What? He had enough fuel to take the flag under his own power, what happens afterwards is generally considered unimportant, unless of course you happen to be desperate to discredit the driver in question. If this had happened to say, a Lotus or even a Ferarri or Renault, nobody would bat an eybrow, different for Mclaren though.
Theres nothing stopping other teams doing the same when they find themselves in the same situation.
I don't understand this attitude in modern F1 where doing anything to claim the 'unfair advantage' is considered illegal, even when within the rules. The teams and drivers want success handed to them on a plate, and there is uproar whenever anbody tries to better themselves through clever exploitation. F1 isn't fair, everyones favourite driver or team dosen't always get to win and people need to cut down on the crying and whinging when they've been beaten.