I think you missed his point. In that exercise, the justifications for the dragons existence are always shifting.

“Oh, it doesn’t show up on thermal? That’s because it doesn’t emit heat. It has special fire”

“Oh, when you spray flour in the air nothing sticks to the dragon? Well that’s because it is also incorporeal”

Skeptics keep asking questions. That’s the point. If you are never satisfied with any answer, you have no reason to believe the claim. There is literally nothing there to believe in.

His point is that skepticism and wonder go hand in hand. One without the other is dangerous. What a fascinating claim, an invisible dragon! It should not be dismissed outright as obvious quackery, but let’s see how much scrutiny it can take

We start with an invisible dragon and the more we look into it we now have to explain fire without heat, bodies without form, etc. gee, it seems that for this to be true our entire understanding of the world is wrong…or is the simple answer that someone is trying to trick us would answer this better.

Then the skeptic starts asking why someone would want to trick us…