Shame on him if he can't get access to the money.
I've hedged several bets like this in the last 20 years. They weren't $100k but in the $30k range. I was able to make nice profits on each hedging.
A few years ago a guy had a huge bet on Auburn football where he could win like $60k. His best friend who was an accountant and another Auburn fan convinced him not to hedge because he thought it would be bad luck. He didn't and Auburn had a huge lead (21-3) going into the half and looking good. Well an FSU hail mary right before the half and a huge 4th quarter killed the bet. I would have killed my friend. I definitely would have fired him as an accountant. You should always hedge, even for a small $4-5k profit.