Circumstantial evidence is often weighed equally as direct evidence. Judges often tell jurys this, otherwise nobody would ever be convicted.
The common example is "If you walk outside and there's snow everywhere, do you ask yourself 'hmmm, maybe it snowed, but I didn't actually see it snow, so I can't be sure, maybe a bunch of guys came and spread snow all over my yard while I was sleeping...'
It snowed. But you only have circumstantial proof of it.
Insisting on direct evidence to prove you wrong is that flat earthers do.
Get them on the stand, with a verified copy of the subpoena, and under oath or affirmation, that it was served. Include the a copy of the Service affidavit, with the affidavit-maker attesting to it "viva voce" on the stand.
All the BS that these subpoena people are doing is to get Trump or some of his people to be scared and cave in.
This would all be circumstantial evidence.
As it is, people get convicted for nothing all over the place. Minor usage of drugs is an example of this, simply because people don't know how to require to face their accuser.
A few, like O.J. Simpson at his first trial, know how to require proof. That's why he won at first.
The witness of a man under oath, with evidence to back him up, is not circumstantial. It's fact until someone contests it with better fact. Then it's perjury.
Without the evidence and the speaking under oath, all we have is hearsay.
You're right. I was wrong about that. A direct witness is considered direct evidence in court.
Still though, circumstantial evidence can be weighted equally. "I saw him shoot the girl" and "I heard the gun shot, and turned around and saw him holding the gun and she was on the ground across the room, and there was nobody else in the building" are equally strong. You can't just dismiss is because it's 'circumstantial'.
And apparently you can't just accept it because it's direct, since you have to take the credibility of the witness into account.