no its not. Its typical lawyer drivel. He says a whole lot, while actually saying nothing at all.
he makes a claim, the GUR using ISIS, but provides no information, data, or back up. he doesn't attempt to explain why they would ever need to use ISIS as a cover, they are already at war and have struck plenty of targets inside Russia, including some civilian. He doesn't explain why the GUR would want these guys to try and return, instead of blowing themselves up in typical ISIS fashion. the only person them not killing themselves helped were the potential victims, and Putin.
He says the west provided little information and lied about what it did say, but doesn't provide evidence. and considering ISIS had video of the incident its going to be really hard to refute that or blame the west unless they can prove ISIS got the video from the west.
He says Russia has provided a plethora of information, but provides none of it. he also doesn't give any examples of how the Russian information was better or right. seems if there was so much good evidence, he could have used an example or quoted someone.
he then makes another useless supposition about the bombing at the grave site in Iran. He mentions three months after the war in Gaza, but neither the dead guy nor ISIS has anything to do with the war in Gaza, so that is useless red meat just to get your lather up.
its no wonder you guys get so much stuff wrong if you think this is reasonable. it provided ZERO information, zero context, none of the claims are backed up, and he literally just throws in some completely unrelated conspiracy notes in the typical logical fallacy of those who buy into every conspiratorial matter. If you deny X, you also deny a completely unrelated Y, because I drew some completely arbitrary connection the two. every point needs to stand on its own, otherwise you assigning value where there is none, and making conclusions before you have any real information.