*edit* Okay, someone else beat me to it. Exactly as a previous poster has described. The other way is to pause the game for everyone else just 1 second (or a time they can't notice) and calculate the desired bet ID needed for the win, then resume, grab that winning bet, and continue as if nothing happened.
It can be programmed in the server to do this transparently, and if no winning bet is found within 0.01 seconds, you can just skip it and try again later, attribute it to variances in lag.
Therefore, my statement is that it is not provably fair for investors, and it is also not provably fair for players. You might as well make it at least provably fair for players, and let investors take the chance that the site operators will not cheat.
Like the other guy said, I am not accusing anyone of anything, just that the way this is implemented is not provably fair for everyone.
I have a feeling they are ripping off players. Currently when you bet, your bet number will be about 160 above the one that is currenly shown on the page. Then, take a look at the all bets tab, some bets are shown to be at the same time but over 10 difference in bet ID, while no bets are shown between them. True, primedice also does not send out all bets, but come on, this is a new page, I doubt they are getting such volume.
I think the site is scamming player, take care.
Then you should look at primedice as the same thing happens there...it's impossible to synchronize everythign to fit so perfectly when you get over 10 bets/second