Your cartwheels is the context.
And the context was someone was listing a variety of possibilities.
At the very far end, he said: "not impossible to defend" that particular option.
Hey, it's not impossible to defend my assumption that you are "xxx".
List you worst case scenario of what you wouldn't want to be accused of.
Based on my interaction with you, I'd say you are a "xxx".

Ok, so this guy is listing the variety of ways people might increase the organ supply. And this IS an option that is not impossible to defend. I could defend it.

Take a guy on a respirator for years. No family. No one taking responsibility for him. He's been brain dead the whole time, no recognizable signals for years.

Someone makes the decision to pull the plug. Who? Who knows. Maybe the nursing home he was dumped into years ago. Someone manages to get a court order to pull the plug. The plug is being pulled no matter what.

Now what? He's got a good liver, lungs, and a bunch of other stuff that will save a dozen people. He's never made his preference known.

Who owns that body at that point, and who gets to make decisions?

I can see many slippery slopes, so don't bother pointing them out. Make this particular decision. What do we do with the body? Give it to a medical school? Burn it? Bury it? And no matter what you with the body, you are making the same decisions.

Does it matter if the decisions are made 10 seconds before final death, as opposed to 10 seconds after?

Now, look at the room filled with people with various conditions that will kill them. Pieces of this guy can save them. Will you be ignoring them during your decision process?