No, an epiphany did!
[youtube]IXLDv-fUINM[/youtube]

Side characters or known more commonly as support characters. People who are dragged into the plot or people who find themselves caught in the cross hairs if that makes sense. 

For example: In [u]Enemy of the State[/u] an FBI agent witnesses the main character enter a shady area they've been watching. He becomes the one responsible for calling for backup and calling the police moments before a gunfight goes off. The character needless to say becomes the main reason the main character doesn't walk out with a shotgun hole in his chest.

[url=https://www.youtube.com/watch?v=W6FRXnmISBo#t=159]Here's the scene if the link properly works[/url]