Yes, have witnessed several panic attacks (and other medical emergencies) during taxiing which lead to severe delays over the years.

One time actually they had to cancel the flight and rebook all pax to the next day since it took so long to get the issues sorted that the flight couldn't depart without violating the night curfew in FRA. All lot of unhappy passengers... Me included.

Worst panic attack I saw on a domestic Swedish flight on a really old and run down Fokker 50. Even I wasn't to happy about flying that pile of scrab metal