I had a very similar thing happen with another book.
Evidently they graded a prop as a winner that was actually a loser. I didn't notice. Continued to play and lost my entire balance (including the money graded as a win).
When I reloaded they identified the error and 'regraded' the wager, deducting the funds from my account. Unfortunately they did not notify me of this, instead I had to contact them. They were able to point out the wager in question and all was well (it wasn't really my money since they made an error).
Something close to this with a VO book. They evidently misgraded a wager, before I realized it I bet the credited win amount. I realized it that smae day on my way home on the train from NYC when I was reconciling my accounts. As soon as I got home I made a neteller deposit to cover the wager I had made (was somehting like I had 500 in the account originally, was credited with a 200 win so balance showed 700 instead of only 300 since it lost; I wagered the entire 700, so before the event started I sent them 400). I called them on the phone and told them what transpired. They appreciated that I took the inititive to send the money in, I didnt geet anything for my efforts, but it was the right thing to do.
I still am missing where they did anything wrong, maybe its just me.