Well if you listen to the video, his statement at the end, "a random teenager somewhere in the world" isn't stated with factual authority. He is
reaching, he does NOT know that for a fact. I don't think it was the Russians but I don't believe his whimpy blame statement at the end of the video.
It kind of discredits the rest of the intelligence of that whole segment.
It wasn't meant to be a "the Russians definitely didn't do it". It was simply meant to convey the fact that the evidence that's been presented that
the Russians did it isn't very solid, and in fact it could've just as easily been some random teenager. It could've even been a teenager in Russia. Or
in the US. The evidence is extremely circumstantial, and everyone on The Hill knows that. I'd guess that's why the response was a few weak sanctions
that Russia laughed at. It would be irresponsible to push a major retaliation when they weren't even sure, so they just did some token sanctions so
they could tell the public hey look we did something.