Sorry no screenie because that bug surprised me.Opponent (AI) had some voodoo dolls on his side and then it casted a pandemonium. My surprise was big as my gravity shield got destroyed after this spell was cast. There was no other spells being cast by the AI. Probably this is a similar bug causing players weapon to freeze if a voodoo doll is getting hit by a freeze caused by a pandemonium.
One possible non-bug explanation would be the pandemonium mutating a creature into something with destroy, possibly even a voodoo doll, making it less obvious. Whether that's what happened or not, who knows.
Are you sure the AI didn't use butterfly effect after playing pandemonium?