All the legalistic points here are well taken, however, in most cases, you would still need to hire a lawyer to file said SJM, and assuming you win, a LOT of judges don't bother much with awarding costs, even when it's blatantly obvious that the case never should have been filed in the first place.PerroneFord:A suit has to have grounds, or it can be dismissed with Summary Judgement before the court date. So yes, there has to be grounds. Probably the only one that might appear here is negligence, but that would have to be filed against the operator since the participants sign no contract with each other.
So while you would probably would win (esp. considering there are very few cases where the buddy has been sued and the buddy lost, and those tend to be pretty egregious cases, which isn't what we have here), it would still cost you a lot of money in legal fees to get to that win. And that's almost as bad as losing.