You should not encourage a business to have a "head we win, tails you lose" policy.
On the other hand, offering something like a 1000x payout for an event that has a 50% chance of happening is a clear and obvious error.
If an error is egregious and obvious, it seems reasonable that a company (in this case FanDuel) not honor the deal.
Similarly, say a grocery store meant to have a "Buy 1 get 2 free" steak sale but accidentally keyed it in as a "Buy 1 get 200 free" sale. Nobody would expect the grocery store to actually give away 200 free steaks to every customer who bought a single steak.
Neither is an oddsmaking posting odds out of line with your perception of thpe likelihood of events—if you are gambling, that's exactly what you are looking for normally.
> If an error is egregious and obvious, it seems reasonable that a company (in this case FanDuel) not honor the deal.
This bet was made over the counter: if there was such an obvious and egregious error, it should have been refused at the counter. Would FanDuel have tested the bet induced by the odds as null and returned the funds if the bettor had lost? If not, why should it get to nullify it when the bettor wins?