...which doesn't go far when shared by a large group of workers pooling their stakes.
You are probably correct. Given 1 BTC=$594.9
Betting 0.025 BTC ($14.87) at 1:10,000 odds yields a jackpot of 247.475 BTC ($147,223).
It would probably make more sense for ten guys to pick positions, and print out the paper and see which position wins. They are much more likely to see somebody win something over the course of a year or two, than just to waste their money on a tiny chance of splitting a megajackpot.
If they agree on a time when the bets will be placed, then the documentation will have the timestamp, and it won't be possible to cheat. Plus you can easily produce the entire history of bets under a name, and so you have a record of all bets. The person placing the bets can't hide a win, and simply do another bet at a later time.
I must be a very distrustful person, but I see stories about lawsuits all the time.
I just object to that 50% house edge.