I didn't know he had only been riding for a couple years. That makes jumping even more dangerous --- it isn't a sport for beginners.
I read his book "Still Me" and he said that he was trying out lots of dangerous sports, the last one being riding and jumping. On another thread, someone said that his trainers were advising him against jumping the courses he was riding, telling him he wasn't ready. Any way about it, he took a big risk and lost.