I seem to remember the classroom doors of my elementary school (I'm in my sixties) opening in to the classroom, so that during an emergency they wouldn't be pressed closed by the panicking hords rushing by in the hallway, and so that opening them wouldn't injure those panicking hords.
You also often see bathroom doors that open in; I had this random conversation with someone at a conference last year. I assume the theory is (assuming there is one) that there would rarely be so many people crammed in a bathroom that there'd be such a crush to get out that it would be hazardous. On the other hand, even day-to-day bathrooms are sometimes located such that someone quickly walking down the hall looking at their phone could fairly easily be slammed into by a door being swung out into the hallway.
