In many cases they can and will if they either feel that the risks are worthwhile (in particular cases where the penalties are far exceeded the potential boon), or if they think they have some sort of edge case loophole that they can throw money at to get through. These are carefully calculated risks planned out by experienced teams of lawyers though.

Something like this though was almost certainly not one of those gambles.

Given yelp's reputation for having a toxic extortionist corporate culture, I think it's naive to assume anything is beyond them. If you told me yelp flat out had somebody murdered, I wouldn't dismiss even that out of hand. Not after what I've heard about their corporate culture, and not after hearing what eBay executives thought they could get away with.