I know this is fine when everyone is being moral/rational. But what prevents someone from maliciously suing the skating (or something more dangerous, such as skydiving) place for something they weren't really responsible for?
Nothing. But to win they would have to show that the company really was responsible for it, since the accused is innocent until proven guilty. The accused can also request a trial by jury; 12 people generally make the right decision.
(Note: not legal advice, and possibly only relevant to the US)
