Tight passive player goes on tilt and plays better

[SNOWBALL138]

I was playing heads up 3/6 7cs on UB. My opponent was folding his king to my deuce, folding my bring in raises when he had a good upcard, almost never bluffing, etc.
He would fold maybe ten hands in a row even. Sometimes, he would check his paired door card, and then fold to a bet on fifth street. It was unreal.

This went on for about 700 hands and he was down his whole 300 dollar buy in. So he rebuys. Slowly, he began to play better. Soon, he was reraising me on 3rd street as a bluff, checkraising me on fourth street, raising my bring in, etc.

He still wasn't playing that good though. I was still getting more than my fair share of the antes, and he began to overplay some of his hands. I noticed also that he seemed unable to read my hand, which is often a sign of tilt. He would cap on 3rd and fourth versus my obvious big pair in the whole for example.

So, I felt that I was still outplaying him somewhat. Part of the reason was that I had two semi-reliable online tells that helped swayed my decisions. Anyway, the more he lost the tougher he became to play against though. The reason is that he didn't completely go nuts like some people do when they tilt. His tilt ended up correcting some of the errrors he was making so that he was playing approximately correctly.

I was going to quit on his, because I thought my edge on him was dissipating, and I wasn't sure I could adjust to his adjustments against me and still have as big of an edge as before. He won a few good sized pots against me, and then...he quits on me!

He left me with only ten BB profit on him, and then he sat at a lot of 7cs tables, waiting to play people heads up. I would sit down to play him 5/10 heads up, and he would refuse. Same thing at 3/6. I think this guy never wants to play me again. Does anyone know if UB lets you change your account name? I really want to play this guy in the future...

Looking back, it was probably a good idea for me to quit on him when he began to play better. If I had, he might be the one that wants a rematch from me! Now, it looks like I've lost his action.

Best,
Snowball