I believe Jaglom. When those clips were first posted, my immediate thought was "what is he doing with footage from TOSOTW?"
Seriously, although Jaglom is in the footage, why would he have the footage? Did Orson give it to him for his birthday? Did he steal it from Orson's closet and shove it down the front of his pants while Orson was in the bathroom and Oja was getting more ice? Really, think about it.
Either Jaglom is correct, and someone posted under his name without his knowledge, or someone with access to the footage posted with Jaglom's knowledge, although his denies it.
The correct question to ask is, who likely had access to the footage?
Gary Graver has left us, so we pretty much have Oja, Bogdanovich, someone at Showtime, someone in Munich, perhaps McBride, perhaps someone at Astrophore. Any other suggestions would be welcome, but I think that's it.
My guess is someone is trying to cause trouble for Jaglom, because of the book. Perhaps one of the people claiming that Jaglom taped Welles without his knowledge, which I don't believe. I think Welles told some people that he was taped without his knowledge, in order to distance himself from some of his more poisonous remarks, which is not the same thing.
Posting this footage under Jaglom's name would aid the narrative that Jaglom was trying to profit, or gain attention, from Welles material that he had somehow "stolen", wouldn't it? You know, like the book?