Read the rest of it. If you can’t find two people who personally witnessed the act of treason as it was committed, and who can prove that fact unequivocally in court, and who are willing to testify, you can’t convict anyone of treason unless they themselves confess. How did you think Reagan got away with “giving… Aid and Comfort” to the self-declared enemies of the US? It was obviously treason, but he just said “I forget what happened” in court and no two eyewitnesses to the same overt act were willing to testify against him.
I’ve often been struck by how much this resembles Sharia laws concerning homosexuality. Apparently if two men live together in a one-room house with a single small bed, and are openly physically affectionate, that’s totally OK in a strict Muslim country unless these men perform an actual forbidden sex act in front of two witnesses - who are then willing to testify about this in court. It’s pretty much “lock the door during fun time and you’re safe” for otherwise law-abiding citizens, even though homosexuality is technically quite illegal and harshly punishable.