Speaking from a position of ignorance in this matter, is it possible that, if all he had to go on was the sort of porn where girls appear to enjoy being reduced to an oxygen-starved wreck by "extreme deep-throat action", he might have (through ignorance or naivety) interpreted her thrashing and choking noises as a sign of enjoyment?
I am in no way defending the man, it's just that, occasionally, this is a bloody weird planet...