Spectator freezing the game?

[Ket]

Had a spectator join a 2 player commander match, between me and a friend. Actually had no idea spectators are allowed by default, but ended up letting spectator stay. After 20 minutes into the game, spectator disconnects and time out countdown starts. As that happens, both me and a friend end up being stuck in a declare defenders phase, unable to select any cards or progress to the next phase, button never appears. Time out runs out, but game doesn't unfreeze and neither of us are able to concede.

Is that something that just can happen?