one little claim and boom, insurance nightmare?

So yesterday I was chatting with my neighbor, and he was all stressed out because he had a minor fender bender - nothing major, just a dented bumper. But he's convinced his insurance rates are gonna skyrocket now. Got me thinking...is it really true that one small claim always sends your premiums through the roof? Seems kinda exaggerated, but then again, insurance companies aren't exactly known for generosity, lol. Curious if anyone's had a similar experience or maybe the opposite happen...