I've helped out on flights before. People are of course appreciative.
Although, one time there were some angry passengers who were miffed that because I suggested we divert a flight (which the pilots did in very, very short order....I had no idea a mainline airplane could land so quickly) they missed their connection. I think these idiots made a point of speaking loud on their cell phone so I could hear why it was just "ridiculous" that we had to divert to get the ill passenger (who was having a stroke) off the plane.
I didn't expect anything from Delta (except a reconnect on my connecting flight of course) but they did send me a nice Thank You letter and a travel credit....I think $200.
You should have said, "Don't worry, I'm sure we would have been delayed anyway by the coroner coming on board if we hadn't diverted." And said it loudly enough that the person on the other end could hear.