I don't know of course, but that should be the default assumption. Parent stated it as fact without basis. It's unlikely that China can break encryption that the NSA has approved suitable for Top Secret data. If they can do that, they already have all of this information.

They could have made multiple stealthy visits and installed keyloggers, but that's also unlikely to work with him.

Put simply, if you work for both the CIA and the NSA in foreign countries as a technical employee, you know how to not get keylogged.