Under some circumstances I have found that just throwing up is not a ride ending event. Sometimes I think I make a habit of it. I did it during PBP in 2011. You'd think you would have privacy throwing up at 3 in the morning, but no, I had an audience. Fortunately it was at Loudeac and they always have super-secrit controls not that long afterwards where you can eat.
Although I can think of a couple of rides where I have had stomach problems and didn't finish. It's really tricky when it's hot.