As I learn more about this accusation, the more I am inclined to fall back on presumption of innocence. He denies it, in no uncertain terms. She says it's true, and there is evidence that she said it many years ago, at approximately the time that it happened, but other than that, there's nothing. Although the story is plausible, there's insufficient evidence to actually reach a conclusion, so in the absence of further evidence, I'm going to say it isn't important.
For the record, that's the same stance I took in the last major "He says. She says" case, and every other similar case I can remember unless I said, "Who cares?"