This happened a few weeks ago but I'm still angry about it so here you go:
My coworker has a nut allergy. A customer came in and was eating almonds. He didn't know it, and sat in one of the (small) interview rooms with her to run through her paperwork. He immediately had a tightening feeling in his chest and couldn't breathe. He ran out and took some benadryl to ease the symptoms, enough that it made him super sleepy and he couldn't drive. His boss wouldn't let him go home because he “only had a few hours left” to the end of the day. They used the excuse that we were pretty slow so he wouldn't have to do much anyway. But we were slow enough we could have done just fine without him.