Cheat or Bug?

[laf]

I played just this guy and he used a red deck before game started.
After countdown the deck was suddenly green, after the first 2 turns he had blue mana on his side which transformed next turn to green. Thats where I made the screenshot.

In the game his critters vanished and were replaced by other creatures. Mostly red/green with a bit blue. I didnt do more screens, next time I will.
The screen is like turn 3, by simply counting the played cards & the ones in hand it shows something isnt right here. He seemed like having much more cards than I.

[Uncle Jellyfish]

This seems like a desyncronization. The person with the Fire Mark probably left the game, and the person with the Life Mark joined, but because of the desync, it never registered it, so what likely happened is that you ended up recieving information from both opponents, which kept overwriting one another. o-o