I once had that happen IAD-FRA. After offloading the pax who was freaking out, they had to find the person's luggage & remove it. The delay caused me to miss my FRA-BOM connection by ~5 minutes, despite my best efforts (running through FRA so fast that I threw up at the gate after failing to make the connection).
Needless to say, I'd love to track that pax down and throttle them.