Revealing mistake: In the lead up to the final scene, prior to the cranes being in alignment, when Spider-Man is jumping between buildings, he falls down to a fire escape, and you can see that the bars or rails on the railing he lands next to are not made out of metal as they easily move as the actor or stuntperson moves next to them. (01:48:42)
Continuity mistake: When Dr. Ratha is talking to Dr. Connors, Connors says, "I'm at a dead end, it's the decay rate algorithm." In this shot, you can see that his hand is elevated off the desk. In the next shot, it's back down against the desk. (00:21:48)
Continuity mistake: In the subway Peter smacks a guy's head against an iron bar, and he falls backwards. A shot later he is standing straight.
Continuity mistake: In the subway after Peter wakes up and gets stuck on the ceiling his hairstyle changes three times in the following shots.
Answer: If you're talking about after the dunk scene, Ben didn't see it as Peter standing up for himself. Instead, he says Peter humiliated Flash and then finds out he's the same one that punched Peter earlier. So in Ben's mind, this was retaliation or retribution, which is not OK.
Bishop73