What this looks like is that you disconnected. While disconnected from the game server, you may still see emotes, card hover and arrow targeting from the opponent, since those are from direct connections between you and the opponent, not through the server. More info here:
Based on the sequence of events, looks like your opponent was continuing to attack you, played cards, etc. When you realize something like this happens, you can quit (Alt+F4 in Windows) and restart the game right away to reconnect to the game in progress. Hopefully you do it fast enough that you have not lost your next turn while reconnecting.