Just thinking aloud, if you are in the process of having an obvious allergic reaction (the lass had taken medication shortly prior to boarding, so she obviously was aware) does she not hold some responsibility? A friend will go into shock if she comes into contact with kiwi fruit. Pavlova traditionally has kiwi fruit, dining out she asked for the sweet without the kiwi fruit. The staff just removed the kiwi fruit in the kitchen prior to serving, but of course the remaining traces was enough to send her into a state requiring the epipen. I know it must be hard for suffers to be so eternally vigilant, but.
Flying out of Dubai on a trip a young lass in front of us on the jetway looked as though she was under the influence of something, or otherwise not well. Taxiing out we came to a stop and spent 20 minutes burning and turning before returning to the gate. The young lass was off loaded and trip resumed.
A work colleague had heart issues and his doctor advised against overseas travel. He went anyway, and while in the US had symptoms that required medical attention. Rather than access the USA medical system and its attendant financial costs, he thought he'd fly home where costs would be much, much lower. Didn't make it, died on board the aircraft enroute. Hard job you guys/gals have to do at times.