Yes, you were clear about why he used Nigerians. Beside the fact that some Nigerians were scamming the whole world over the internet not too long ago (I even watched a Nightline episode about it), I didn't know that there are Nigerian gangs in SA right now terrorizing the populace, so my reaction would have been "He's using the Nigerians as a joke!", thinking about the internet scams. In fact, I did read a reviewer who thought the same thing -- thought of it as almost comic relief, not just because of the internet scams but because they were so "over the top" crazy.