Game goes quiet, no more voices, some triggers break

About 7 minutes into a co-op game on Chain of Ascension, something must have gone wrong because the game went quiet, no more voice lines would play (from ANY source - units, commanders, announcer), and some of the triggers wouldn’t work (specifically, the 2nd bonus objective wasn’t listed on-screen until I completed it, and the victory sequence failed to play). Also, Jinara wouldn’t get off the screen. She just stared at me for the rest of the mission.
The other player said he was experiencing the same thing.
I know this bug is really low priority because it’s super rare and isn’t game-breaking, but I’m super curious to know if anyone can explain what happened.
Also can someone tell me how to include the replay in a bug report? I can’t figure it out.

Upload to dropbox or something and then paste the link to dropbox. Surround the link with ` (The grave key, next to 1) on both sides.