Sounds likely if the aide is sworn in as a witness, the aide is not bound by the same regulations, or bound by letter. Interesting
He's not though. He's only there as counsel for Mueller (meaning, he's not under oath and can refuse to answer any questions as he's not the one there to be questioned).
Which that NYT article makes it sound like Mueller wanted him sworn in but the Democrats refused but offered to let him be "counsel" during the questioning.
No one knows what to make of Mueller's request (i.e. was he trying to enable someone else to be able to say what he wouldn't? or was he just looking to maybe take heat off himself?). Guess we'll see. But effectively, now Mueller has to be the face of whatever is said (which if I had to guess, is not what Mueller wants, I think he'd be ok signing off on any of his team doing so, but for whatever reason he just does not want to). The Democrats made a calculated risk, and I'm not sure if its because they wanted to force Mueller to have to put his name behind what is said, or if they did it to appease the Republicans throwing tantrums claiming the Democrats are going outside the accepted norms and trying to appear like they're being objective and non-partisan. If its the latter, they should know better (and should come right out and say that there's nothing wrong with it and that so what if its not normal, the entire situation is not normal and it would be a dereliction of their duties to let someone so credible and willing to testify). If its the former, we'll have to see how that turns out (will Mueller just give "reference my report for our findings" kind of answers, or is the guy there to help Mueller craft hedged answers, or is he there to give his take on the situation and have Mueller go "my team feels this way" and gives concise answers to questions like "if he were not President would you have indicted Turmp?" or "in your view, did the President commit crimes?", point blank stuff that can't be dismissed by Republicans - meaning if they want to claim that Mueller lied they're gonna have to take him to court and I think that's something they don't want as I'm pretty sure he'd tear the fucking assclowns a new asshole in any court proceedings).
Which this guy was requested to meet with both of these panels but the DoJ complained. So its not surprising that Republicans are going apeshit as they definitely seem to view him as damaging to their obstruction.