Asking for a friend (of course) who had a near miss at a roundabout.
Car A was approaching a roundabout and car B is approaching the roundabout from the right. Car A slows down expecting to give way to the right but then sees car B has the indicator signalling to turn left.
The car A proceeds to go straight but B doesn't turn left and also proceeds straight with the left blinker still on.
If there's an accident, who's at fault if they both entered the roundabout at the same time.
Car B's a (profanity) (sorry if it's your friend) Car A's an idiot for not assuming, Car B would be a (profanity). Always assume the other driver is completely incompetent and is doing everything wrong, and you'll be much better off.