My guess would be that the tungsten interior is just a slug. Just Google gold plated tungsten, and there are lots of ads for high quality plating.
Basically, there is no evidence that it has EVER been done, aside from a few sites claiming they can maybe do the impossible, or that one should watch for it.
I don’t see any technical problem in doing so, and the video noted not just how such coins are being passed, but how they are being traded in the US right now.
And I’ve made no mention of brass at all. Where did that come from?