Rapid Decompression. Did the masks drop? This happened to a friend of mine and she started having all kinds of sinus problems afterwards. About 2 or 3 years with dealing with all kinds of issues, they finally did a CAT scan and learned that the decompression incident caused the lining of her sinus to tear loose.
Nah, no masks. I think the sensors catch this sort if thing waay before it becomes a problem for humans. I guess they alerted to a rapid change and the pilots didn’t waste any time diving at a 45 degree angle (or so it seemed) to get things okay. Pretty surreal watching the flight attendants all sort of freeze for a second with a confused look on their faces and them all run for their seats.