He probably did it
Anita Hill passed a lie detector test. They are around 98% accurate, so either: A) she's one of the 2% who tricked it, or B) she's delusional and believed something happened that really didn't happen. If you are to put bias aside and just look at it logically, you would have to assume the likelihood of either of these things occurring is very slim. Is either impossible? No, but maybe a 5% chance, and that's probably stretching it.
Also, back in the day, this is just something many men did because they didn't believe they were doing anything wrong. In 2016, most men wouldn't try it because they know they'd get nailed. Back in the early 80s when this supposedly occurred, there simply wasn't the fear or awareness.