Has anyone ‘confirmed’ his side of the story to you other than himself or any of his relatives? The possibilities are:
* that it is as exactly as described, and that the woman has issues or is an attention seeker
* that the lad is a sleaze, thought an older woman would be flattered and an easy mark, and is now trying to justify his behaviour (possibly even to himself)
* that the lad is one of those clueless types that mistakes a woman being friendly as being a come on, and woefully misread the situation
Probably best to leave the HR department to investigate before jumping to conclusions.