My understanding is that they only met at meet-and-greets/conventions. I need to rewatch those parts because I remember seeing someone in chat saying "but you 2 seemed to get along at twitchcon" but I don't remember if that happened before he started donating/acting weird.
Yeah money creates the weirdest dynamics. The more she kept talking about this guy, that more I was getting the impression that she, like many other streamers, chose to keep the guy around and talk him out of this weirdness instead of getting rid of him asap mostly because he was an hardcore oiler.
I've seen this shit way too many times to think that it's a coincidence: if you're useful to the streamers in any way (tech support, mod duties, money/gifts) they'll pretend that the weird shit you say or do didn't happen so that, in the best (for the streamer) case scenario, the guy gets anxious and decides to "fix" whatever problem he thinks he's caused by sending money their way.