The distinction between a "thought experiment" and a "simulation" is fuzzy, and we can argue about how important the differences between the second and third versions of the story are.

But the first version of the story, where an actual drone supposedly turned around and deliberately killed a US warfighter, goes well beyond credulity. If something like that happened, it would be HUGE, with congressional-level investigations over many months, not something casually mentioned at some conference.