The way the injury reports work is, if a player is not listed on the last one before a game, he is essentially considered 100% healthy, meaning that whatever injury he had was healed. Not 90%, not 80%. Healed. Meaning it is no longer a factor. He was removed from that report on Friday.
The fact that he was in for only three plays indicates that the injury never went away, and he and the Chargers should have acted accordingly before activating him for the game. He obviously didn't go through a full pads practice and get hit before the game, or else they would have realized that he was not fully recovered. If he was held out of such a practice, he should have never been taken off the injury report. Plain and simple.
Now if he did go through such a practice and deemed himself ready to play, and then gets hit in the game and decides he can't play, you can see where the criticism is coming from. If he was able to handle it in practice, why wouldn't he be able to in the game?
I'm merely pointing out that such inaccuracies do not cast him in a favorable light.