[GAMEPLAY] Ryze Bot Bug

I was playing a bot game for my first win as Nidalee mid vs Ryze. After killing him 4 times in lane, he never came back. I figured he just went to another lane, as I was also roaming, but he wasn't gaining levels either. After a couple minutes, I found him at his fountain spamming Q just to stack Tear. He sat there the entire rest of the game spamming Q even as we were winning. Hitting him with a spear didn't make him move, either, and he wasn't stuck on a wall or anything.

Unfortunately, I haven't been able to recreate it in a custom game or get a screenshot or video in game. This is a screenshot of after the game: http://i671.photobucket.com/albums/vv74/DDRMaster_photos/Ryze%20Bot%20AFK_zpsjdqhktow.png

One thing I thought might have caused it is that he only had exactly enough gold to purchase Tear and no other items, as the first time I was unable to replicate it, he came back with a Ruby Crystal as well. However, in the next game, he only had a Tear but still came back to lane.