Sometimes the cash out option is there, but the Casino doesn't want you to cash out the game. In the guise of network or sometimes freeze the cash out option so that, you can't cash it out. I have experienced this type of situation but in my own the games that where not going according to expection all played what I have bet it to be. So I won everything, it was at this point that I noticed that I could cashout the game. I just feel that this was a deliberate attempt to frustrate you by the Casino.
In as much I'm being careful not to blame anybody cause I don't have a good evidence to back it up, I'm a bettor, and the truth is that Casinos can be funny and very tricky at the same time and some times these tricks of theirs doesn't favour them, I have experienced this, but in those experiences, I won most times, they did this same thing to me last week, but I didn't bother myself, infact I stop trying to see if I can Cash cause I was somehow sure of the outcome of the game, and I won that slip after those their the more you look the less you see tricks, as a sports bettor, I have seen this happen severally.