I was battling a medium opponent with my T11 for battle quests and easily defeated him as I knew I would. I hit see results and an error popped up saying "invalid conclusion" and kicked me back into the battle. Never saw this error before, I don't know how the "conclusion" was invalid, I won he lost. Battled again, won, hit see results and again got this message. I did this a third time and it finally acknowledged that I won and let me return to BQs. I got my next challenger then got an error saying I was already in a battle when I went to fight him. I went to the battle it said I was in and again that previous opponent who just didn't want to accept he lost had zero health and now my pet had zero health and it said we tied.

Apparently the game or the opponent cannot accept the fact I beat him repeatedly. It's annoying now that I have to go and heal my pet now to keep battling, but I am more worried about this happening with the harder challengers that take longer to beat.