It's called circular reasoning. Conclusion cites the premises, which in turn the premises cite the conclusion. Evidence (or lack of) is used to prove it self. When you start with a false or circular premise, anything that follows is technically true. It's a powerful (bullshitting) tool that can be used to prove or disprove anything.
It's bayesian reasoning. If I tell you that I predict the sun will explode tomorrow, you should consider the sun's track record of not exploding when evaluating my claim.
There's no bayesian reasoning here, just someone assuming something to be proved to be already true. Statements don't become self-evidently true just because someone assigned probabilities on them.
Also, using only past billion occurrences of the sun not blowing up, and then still concluding that the sun will not blow up despite of any recent indications of the sun showing anomalous activity seems a more accurate analogy.
Mick West presents rational reasons for why his assumptions are true, he's not simply asserting his assumptions as correct.
> despite of any recent indications of the sun showing anomalous activity
The whole point is that the videos are not in fact the indications of anomalous activity that they're made out to be. There are mundane explanations for all of them.
