If the stereotypes are based on race, how are they not racist? They always have connotations, even if the people using them aren't aware of it; if the other group is called "clever", they can't be trusted because they're sly and duplicitous, if they're natural athletes, they're better fit for physical work (and they're more likely to go after your wimmin), etc.
In this case, to me the most striking thing is that none of these people talk. They're silent, obedient until they run away, but the depiction of their behavior there reminds me more of cattle than of human beings. There's also the fact that Fantomah calls the "crooks" thieves and murderers (because they shot the planes), but not slavers. She seems to be more upset about the robbery of diamonds. Of course, that's mitigated by the fact that the ending image is of the village returned to peace.