[dragonwriter]

> Yes it is the null hypothesis.

No, its not.

> The poster is making a positive claim without evidence.

True.

That doesn't make the alternate positive claim you have posited into “the null hypothesis”.

A null hypothesis is null. What you are stating may be your prior, but it is not the, or even a valid, null hypothesis.

> This is a rational use of ‘null hypothesis’, but it also matches the scientific use,

“Null hypothesis” is a very specific scientific term of artz it has no other meaning.

And, no, the specific counternarrative presented here does not match the scientific use of “null hypothesis”.

[zepto]

You are still wrong. I don’t make a positive claim.

All images that do not actually trigger detection are fakes in terms of the poster’s claim.

That’s not my prior. It is the null hypothesis for any set of randomly selected images.

The poster’s claim is that the images have a special property. That is the positive claim which they failed to provide evidence for, and is logically false based on their description of the method.