Maybe all your tail lights were out and he wanted to tell you and to make sure you were safe, he drove behind you since he was aware of the issue. You then tried to ditch him but he found your car in a parking lot, but you were acting weird so he didn't want to approach you.

Just a thought...same thing sorta happened to me, but I was the "crazy following guy". They had pulled into a well lit gas station and pretty much said "why the hell are you following us?". I told them their lights were out and drove off before they could thank me.....or flick me off.