I don't think anyone has used the words 'dangerously pathological'. The kind of behaviour we are talking about here has a massive spectrum, and as I said before, I think OP is not a threat, and is at the mild end of the spectrum.

But- having had a colleague sit in a car park spying on me - Hell yeah - Thats threatening! I don't doubt for a second that the OP's intention wasn't meant to be threatening - but there is a very realistic possibility is that it could have been interpreted by his T as threatening behaviour. Its not counter productive to advise him to prevent this by talking to his T. Its positive encouragement to OP to turn this situation in to a constructive and healing event, rather than to sit on secrets and shame and let it spiral in to something worse.