I suspect what really biased the top ten horses were that they were well-known horses and when people came to visit them in their stables, before and after the race, they did tricks for them. The sheikh may have made a mistake of letting these visits to the stables influence the race, because the sheikh's normal races are not about winning but camaraderie.

Definitely don't trust a sheikh, and especially don't trust that they're infallible, but I wouldn't assume they're malicious and meddling when the results could be just as well explained by a flaw in the race design.