It's amazing how they treat people, especially mothers to be and nursing mums or any parents with small children.
I'm not sure which is more amazing: that he would tell a third-trimester pregant woman she couldn't sit in a chair or ride the elevator, or that he lived to tell about it. Just speculating, I doubt the hall monitor you encountered was married--husbands learn quickly to not do such things, or they won't be a husband for long!