I never understood the guys that dont trust the woman with the orgasm. (how bad could she fuck it up?)
You mean when the guy pulls out of her mouth and jerks his dick to ejaculation?
Some guys just can't get to orgasm through oral sex.
My ex and I tried many times. I could only succeed by getting into a position where I could thrust my hips.
These actors could also be on antidepressants, erectile drugs, etc., and it could be their 2nd or 3rd ejaculation of the day. All that can complicate reaching orgasm on cue, without the familiar feel of one's own hand.