Didn't Hamilton take a trip through the gravel today? Just luck kept him out of the wall, it could very easily have been a Hamilton DNF from the lead.
I have to say Hamilton's only real mistakes in the past few years are "tactical" ones that are basically his teams decisions, not his.
He hit the gravel today, but that was in changing track conditions as he tried to do two things, maintain the gap to the guys behind him, stay competitive on time with unknown conditions. Hamilton needed to go faster than the guys behind him, honestly, Alonso just wasn't under the same pressure because of where he was, losing a few seconds wasn't going to make ANY difference, so he wasn't pushing as hard as Hamilton.
Hamilton locked under breaking into a corner in changing conditions, ALonso hit the curb, which is a HUGE problem in the rain and he started accelerating with his rear tire on the curb, thats schoolboy to be honest and completely different. Any old driver should know, wait 2 seconds when all 4 tires are on the track before going, Alonso maybe a schoolboy error under no real pressure to be that fast. Hamilton made a far more understandable error in changing conditions while under huge pressure to not do an overly slow lap.
The only thing I'm a little unsure of today is, why did Button look SO competitive with Hamilton in the first lap, and the first few corners after the restart, he was bearing down on Hamilton and right after that, I'm not really sure when his "damage" occured but it didn't seem to affect him at first, then after a few laps Hamilton just pulled away like they were in different cars altogether(much like most races this season).
I did honestly wonder if the "your wing is screwed, switch to F setup" wasn't code for, haha, Hamiltons away, Webber's boobed up, use our F setup which as you know, isn't quite as fast but kills the airflow behind the car making it extremely hard to pass you
Then again in qualy yesterday, almost everyone was significantly slower in those last laps as the track was getting a little wet, I was very surprised to see Button go faster in those conditions, though Hamilton improved by a much bigger margin.