Is it appropriate to make a pun that references a highly charged topic in current events, in a lecture on an unrelated subject? For example, when discussing red-black trees in lecture, is it appropriate to use the phrase "Black Nodes Matter?"

The proof that red-black trees are balanced relies heavily on the property that each downward path originating from a node contains the same number of black nodes.  Given this, I am wondering if it is appropriate to say #BlackNodesMatter.
This would be very unfortunate. People across the political spectrum have strong feelings about the words Black Lives Matter. Indeed, the subject matter of the movement is literally life and death. It's not something that should be made light of in mixed company, let alone in a classroom.