Revealing mistake: When Trevor is stabbed, we can see the knife isn't in him, it's just pressed against his shirt.
Pay it Forward (2000)
1 revealing mistake - chronological order
Directed by: Mimi Leder
Starring: Kevin Spacey, Helen Hunt, Haley Joel Osment, Jay Mohr, James Caviezel, Jon Bon Jovi
Continuity mistake: When Helen Hunt is in the kitchen, while Haley Joel Osment is eating sweets for breakfast, her hair is in a mess, but in the next shot it is noticeably neater at the front.
Eugene: Jesus Arlene, he doesn't have to. All he has to do is not love him.
More questions & answers from Pay it Forward
Chosen answer: The one who stabbed him was not. The others were there because they did not mean for Trevor to get stabbed and killed so now they feel guilty. They were showing Arlene they were sorry.
They were sorry for killing him.
Only one of the bullies killed him. The others were bullying, but didn't think the other would kill him. However, they still had remorse and were showing that remorse to the mother.
The one who stabbed him was probably arrested offscreen.