The chances of them being "interested" are minimal, but that's only marginally relevant. They're obliged to attend if there's been a Road Traffic Accident. And if you don't call them your insurance company will almost certainly deem you to have been guilty. Calling them is your only realistic defence against being accused by the other party, behind your back, of actions you didn't commit. And if you haven't called them, your insurance company can't fight your end. Copious contemporaneous photos from the actual scene are an enormous help. Especially photos of the culprit if you can get them without being assaulted :-). It's psychological warfare.