The other one was me. I felt ill on the way down but figured I would take some ibuprofen and do the swim. I did and felt sick but the stomach pains had gone, I did lap one of the bike and was doing ok til pain came back the last 3 miles of the bike were done at 9mph! I figured I would quit before I was left out on the course all alone, which was the right idea, basically went home and slept the rest of the day.
A note on the swim, if you can front crawl dont put yourself right at the back because you will get stuck behind a wall of breaststrokers who are bloody impossible to get past without sustaining injury!