Snaike: The ball rolling up to the cartpath is a known bug.... Immovable Object, Free Drop, Lost Ball...
That is correct, but in those situations you aren't returned back to the teebox, you're just set behind the cartpath. He didn't mention a lost ball either so this may be a bit of a different situation. Hopefully ES can provide a picture of the area he experienced this and we can look a little closer.
I'm thinking that the drop logic is getting involved here. It's likely that there was no legal place (not closer to the hole) to drop the ball in bounds 1 clublength from where it was, which would explain why it was returned to the tee. Without checking into it further though there's no way to no for sure. Hopefully he submitted a bug report because that would tell us the exact the point where the ball stopped.