I've read other threads that obviously seem like desynch issues but I don't think this is one of them.
I was playing PVP using a variant of the super vampires deck and my opponent, who I will name if anyone in authority cares as I suspect he was manipulating the system somehow, began by accusing me of using the trainer to cheat somehow even though I had only used a few Quantum towers and an enchant artifact on them. After realizing that he was doomed I saw something flash on my Towers with the word "Paradox" floating up from them and they all disappeared even though the icon for invulnerability from the enchant artifact remained. I received nothing else from them the rest of the battle. As soon as I responded to the player asking how invulnerable towers disappeared he d/c'd from the game.
I don't think this was a bug but there is not a "report cheating douche's" area and I could be wrong so here it is.