In DDQ, The Big Enchilada, right as wave 3 dies, the enemy Sentry appears on the screen casting his red skill, doing damage to my entire team. I noticed that the newly appeared enemy team took no damage, and that my strike tiles on board are still in tact.
Likely there is some kind of bug with the wave changing and enemy Sentry skill (destroying tiles and ending turn) somehow did not register any tile destruction.