Heroes dead / Tourney shields

During the last days I had this occur at least three times.
I play a match (PvP of any sort), then skip through some of the matches on the selection screen. I find a worthy opponent and click FIGHT. I enter hero selection and all of my guys are dead. I just came out of a fight with almost full health and now they are dead. I only encountered this since the introduction of the tourney shields. I cannot assure you that it only happened after I saw the »-0 points« screen but I would bet on it.

Anyone else got that?