Happens all the time, but if there were ever a hint of a patient, of whatever sex(!), coming on to one of our GPs, I am sure they run like a rabbit caught out in the headlights, fill in an incident sheet and it would go on the pt's records as a warning to others.... None of ours would act on it, or do anything rash - they;re all far too scared of litigation like you said.
I haven't heard of it happening recently - though have heard references to such events decades ago.