I experienced something similar while I was lagging...
It was really weird.
I was playing a CCYB deck in PvP2, with a voodoo deck.
1. I lagged, and a rapid click caused me to play a GPull and a SNova at the same time. Next turn I got an extra SNova.
2. My opponent played his game and won, but this type of desync happened, I think.
3. My turn was skipped after the discard message flashed quickly O_O. He played 2 turns in a row.
4. He fractaled lava golems. Shortly after, every single creature in the bottome two rows flashed targetting screens and died 1 by 1.
5. They all revived as 0 | 0 creatures, which disappeared on the AI's next turn.
It was all really, really, weird.