I'm not sure if this is a bug or not, but I don't think I've seen it before, so...
I was training a character in the lower ice caverns today, and I was getting a much higher than normal number of 'oops you accidentally double clicked or hit back, so a round of battle was not shown here' errors.
In itself this is not too strange, but I also saw that error once after clicking Quick fight (no XP) and even once after clicking Retreat.
As I said, not sure if this is a bug or not but I thought it might bear investigating.