Lots of things are entirely possible; many fewer have any tangible evidence that they actually happened.

If you trust Edward Snowden (a lot of HN users appear to), wouldn't his leaks be tangible evidence?

Those would be tangible evidence that it's possible, again, not that it happened in the Chinese supply chain as alleged in the Bloomberg story that hasn't been retracted yet.

Bloomberg didn't say possible, though. They said it had happened, and been discovered.

Specifically, they said "A major U.S. telecommunications company discovered manipulated hardware from Super Micro Computer Inc. in its network". And then that manipulated hardware was never produced and verified, Bloomberg provided no evidence for the claim, every outside investigation disagreed with it, and their primary source criticized the story (in favor of an even broader, equally unproven assertion).

It's an interesting theoretical attack, but Bloomberg made specific, concrete assertions which are, according to all available evidence, bogus.

https://www.bloomberg.com/news/articles/2018-10-09/new-evide...