I can explain the different results with the slightly different moments at which the market is refreshed when you restart it over and over again in Time Machine. Because it cannot be reproduced to a millisecond, as a CPU cannot be relied upon with that precision, you query the market's prices at different moments each time.
Like in real-time mode, two users betting in the same market with the same strategy can get different results, as it is impossible to get prices and post bets at exactly the same time.
Hope that makes sense.