Vegan

The wikipedia article on Buddhist vegetarianism covers everything here. You can see from some writings that Buddha had made some concessions of eating animal flesh for members of the sangha, but that was only because of their specific context, where they were operating outside the normal economy and relying on receiving alms. Another passage sets further restrictions on monastics:

"… meat should not be eaten under three circumstances: when it is seen or heard or suspected (that a living being has been purposely slaughtered for the eater); these, Jivaka, are the three circumstances in which meat should not be eaten, Jivaka! I declare there are three circumstances in which meat can be eaten: when it is not seen or heard or suspected (that a living being has been purposely slaughtered for the eater); Jivaka, I say these are the three circumstances in which meat can be eaten."

Another text further declares that there are five type of livelihood that the lay follower should not engage in - one of them is the selling of animal flesh.

So to situate these requirements in a modern context, it would be like a person living a vegan or vegetarian lifestyle to the best of their ability - but also accepting whatever the food pantry has to offer, or possibly going dumpster diving and eating whatever they find. The point is to seek to do the best we can, as much as our circumstances allow.

In Mahayana the injunctions against consuming animals only gets more direct and unequivocal. And in general Buddhist ethics are naturally very aligned with at least the reduction of suffering side of vegan ethics.

The example in your video sounds like it was largely a socioeconomic matter - they do what they can, with what they have. Of course it could also be, at least to some extent, that they haven't engaged with the matter enough to move away from oyster consumption. They might not have a central nervous system, but things are not so cut and dry.

https://en.m.wikipedia.org/wiki/Buddhist_vegetarianism

https://m.youtube.com/watch?v=zvE7W1l8wfY

I'm sorry, but if the insights of a respected and accomplished Standford scientist, who routinely contributes original science on the relevant subject matter, is spreading unscientific lunacy - then what exactly counts as good science to you?