How is any of that relevant unless he intended it to be racist though? It either isn’t meant to be racist and I could see how that could be funny or it was meant as black baby is a chimp, how would that be funny?
The problem is that a lot of people disguise their deep rooted hateful racism as jokes, it’s how a lot of propaganda can be spread. Look at the effect of 4chan and 8chan on racism online and especially in the US.
I don’t he intended to be racist and think his sacking is harsh. But that doesn’t mean racist jokes aren’t bad.