The critical point here will be if you can be proved negligent, if you can then any claim would succeed, if you can't, it won't. Insurance law (and yes I did work in this field for many years) says (in brief) that if there is a reasonable expectation that an accident might happen, then it can be expected that it might, and you need to do something about it, otherwise you are negligent. If in your instance the client say tripped over the leg of a rowing machine, then they knew the rowing machine leg was there and could reasonably say that this was an accident and nobody's "fault". As others say, if you should receive a letter from the person or their solicitors suggesting that a claim is being made, just acknowledge it - making no apologies, that is important - but acknowledging receipt of the letter and saying that you are passing it to your insurance company, then send the letter on to them straight away. They are set up to investigate everything like this. Incidentally, I hope you recorded this incident in your accident book when it happened?