My understanding of humour is that it might be funny to some but only rarely to all.
It reads as is he was reciting a real event in his life, an incident that he looks back on with humour [he may be making it up of course]. He is passing this on to the audience.
Humour is supposed to touch nerves in one way or another I guess this 'joke' meets some measure of that and I have heard some black humour in my life from time to time. I did not like it all, was 'upset' by some, but I did not go to running a vendetta like this!
Tell a funny about the Last Post and you may upset the people closest to its meaning... in this case a Royal Marine or three.
Tell a funny about a same gender relationship and you may amuse a heterosexual but may alienate the people closest to its meaning ....
Tell a funny about an Irish person... and these days you may well go to prison unless you were born in Ireland...
But I guess you are not telling us that all humour is to be banned.... are you?
Now is this Rotorheads or talking heads?