I just had this issue today, actually.
No blockbuster was used, I have a (never fought before) valentine [scrubs] in the first story mode mission that you can have a single fighter in. I was fighting a rerun peacock, who hit me with a pie to the dace JUST as I hit her back [damned type advantages, or I would have won]
It did not say that I had won or lost, but the game instead froze with both of us crumpled on the ground. I personally consider this a loss, but thought it was worth sharing.