Could the spear be an element added to the story for color, or could it be someone on the transition team said, no spear! We don't want to alienate anyone, and the joke potential is too high!
Actually I think it would be cool, since that IS his cultural background, much like giving pipes or a kilt with dagger to someone of Scott descent.
The difference is that Scots are not still out there killing each other with their daggers.
Actually, maybe she should have brought some tires and gasoline as her present. Any African dictator would love an additional supply of those items!