There's another way to look at that as well. According to some of the summaries, Robinson used the same threshold as what would be used in a civil trial. So the assumption is that if Watson's civil cases ever went to trial, he'd probably be found guilty (at least in 4 of the cases).
I'd argue that you're unfairly leaping past the point that all language was defined by the NFL, and the judge was bound by their "post-hoc definitions". That would be a pretty early box on the flowchart that may prevent predicting what would happen in a court of law. Is it possible his actions would even reach a level of "sexual assault" in many venues?