He completed a whole European tour, went home, turned 70, discovered the disease and died. That's as close as it gets to actually die on stage. No offense intended but if it had happened that way, the song should have been Killed by Death, ha.
Anyway, I found the whole "He discovered two days ago he was sick" weird, it reminded me of Freddie Mercury, "I wish to inform that I have AIDS" and then he died the day later... but the comments from his doctor make sense, so after all it may have actually been something discovered at the very last moment.