Not the GP, but this kind of thing can happen all of the time. The people experiencing the bug don't know who is responsible so they arbitrarily pick someone.

Not the GP, but this kind of thing can happen all of the time. The people experiencing the bug don't know who is responsible so they arbitrarily pick someone. The bug could get passed back and forth endlessly between teams until somebody isolates it a little better and bisecting is a good tool for doing that. Just doing the bisecting rather than arguing with the other team about who should do the bisecting is a way to get things done. If it does turn out to be the other team, it may be easier to convince the other team to take on similar requests in the future.