Level desync and cleared team

[Ulquiorra 1]

I challenged someone to battle and when we started, something was wrong with Pokemon levels. For me, they were displayed correctly, but the other player's team had normal levels, instead of 100s like in all online battles.

The battle then desynced, because on other player's side, their Pokemon dealt less damage than they should. He casually Alt+F4'd the game and I tried to battle again, but he couldn't wait for battle, because his first Pokemon was unusable. Eventually turned out that problem was this:

His team was cleared, all Pokemon gone. He was able to restore the save from a backup though (which had the same creation date as main save, for some reason).

 

Not sure if these two are connected and not idea what caused the original desync, but well... it happened. We had another battle with the same teams before, the only thing that changed was field.