I run a FFQ deck and I've never been able to do more than one firefly per queen per turn. Could be that they have a lot of fireflies in the deck and are just playing them all at once?
I have run into the targeting bug a few times.
Two others that I've seen are an auto-win bug, where my opponent's timer runs down and suddenly I win. At the start of the next match, where it shows you the health and quanta of the previous opponent, they all read NaN - Not a Number.
I've had exactly one battle where it seemed like everything was bugged to the max. My opponent's permanents were untargetable. His Empathic Bonds were healing him almost 20 per monster (he had two, so it was 40/turn). And he was getting healed to full without playing Miracles - I know he wasn't because he had no Light quanta. Weird battle....