My understanding is that this is not correct (your comments on the difficulty of programming an RNG notwithstanding.)
If you can assume a magical perfectly random algorithm for a moment, you simply have to design a slot machine as follows (simple example):
Machine takes $1 bets only. Machine "rolls" a virtual ten sided die. On the number 10, a jackpot of $9 is paid. On any other number, the bet is lost.
This machine would make $1 profit for every $10 wagered, over time, "guaranteed" (by mathematics, not rigged programming) and would never need to be 'overdue' to hit or any other such nonsense. A customer could get lucky and hit 10 jackpots in a row, but the odds would be fairly astronomical.
Incidentally, such a machine would be a pretty bad bet compared to most Vegas slot machines, but I think still a high enough payout to be legal in Nevada. I think it would be roughly comparable to the odds on the bad machines in the McCarran airport...