> Perhaps it didn't "start" with "off-color ribbing" but the usage of 'jokes'

Hutus and Tutsi violence didn't start at jokes. It started with German and Belgian colonists literally preferring one group over the other. Raising animosity between two groups of essentially genetically same people.

Hutus used the identity cards colonists left to target their purges.

I'd say those influenced genocide way, way more, than some radio jokes.

Edit: I think it's easier to believe that if we didn't make a jokes here and there we could have prevented an atrocity. It's an easy and quick solution to a complex question.

I think the situation was way more messy and way more muddy. Jokes didn't help but stopping them wouldn't have stopped the genocide.