It's not the senate, it's staffers, from the minority. It's Republican staffers.
It's a politically motivated report and not even close to a senate statement.
\sarcasm (in case it wasn't obvious)
Anyway, I think what you were really told was that there was absolutely zero evidence but a lot of innuendo.
The fact that China is sticking with a zero Covid policy makes one wonder if there’s more to the story but when it comes to facts, we seem to have very little actual information.