About the cavitation talk--I don't buy it. Ballistic gel may do a decent job of simulating the average density of the body, but ballistic gel is uniform throughout. Water moving around in the body encounters things as impervious to it as bone, and it encounters actual cavities. It does not move through all of it with equal ease. Just the difference between moving through muscle and fat is considerable. If you don't believe it, try cutting meat and see if that's as easy as trimming fat.
And yes, air being compressed by a small but very fast moving object will flow up, down and sideways when it's trapped between that irresistible force and an object it can't move, like the base of a human skull. It'll get under a collar and it'll fill up a piece of cloth faster than it can bleed out through the weave.
The contention that water and skin can react faster than air and woven cloth is silly. The official excusemakers for the implausible official narrative point out--rightly--that air is much more compressible than water. But water still can't move instantly through muscle, and it's a lot of work for it to separate muscle and skin. Water will travel a long way around to follow the path of least resistance. The upper back in the vicinity of the shoulder blades is one of the most muscular parts of the human body. It's not where the most fat is stored, and Kirk wasn't fat.
Besides, cloth won't hold compressed air, but it slows it down. Cloth puffs up first, then lets air out. And it was a loose shirt. So it's much more believable to me that a bullet would shove air under a loose collar. Remember, the theory that his skin expanding very briefly due to cavitation and retracting faster than the cloth can depends on air being sucked in between the skin and cloth. How does it get in that fast? Cloth can move as fast as skin can. Cloth isn't so stiff that it will stand off from the skin and air will rush into the vacuum--at least that shirt obviously didn't have that much starch in it. This guy says a bullet can't pump that much air in under a collar that fast, but massive cavitation leaving a vacuum can cause air to be sucked in that fast? Under a tee shirt?
As for the puffing in front, no bullet is needed to explain it. The puffing out in back pulls the collar up and tight. The cloth right under the collar in front pulls that part of the shirt tight to the chest, visible in the way it pulls the lettering on the shirt into an arc. And since it's a loose shirt, the air is shoved out from between the cloth and his chest. Some seeps out through the weave, but it goes all directions, including sideways.
They talk about a necklace, but I think what we're seeing is his ear bud and wire. One of those can go flying easily. It doesn't have to be broken because it's not a circle. As for the lavalier mike, if it was just a little bomb or if there was a tiny gun in it, we'd be able to see a flash. Anyone who has ever shot a gun knows what recoil is. The man was wearing the thing. If it was heavy, he'd have smelled a rat, it would have tugged his shirt down harder, that little magnet might not have held it. If this very light device had exploded or had recoiled, that little magnet would have gone flying in a tiny fraction of a second. It didn't. That little device would have gone somewhere in a big hurry if the recoil from launching a bullet acted on it--probably sending it tearing through the cloth. That didn't happen either.
I don't know what happened. This evidence, combined with what has been leaked about the autopsy, concerning the highest few vertebrae, makes it seem to me to be most likely that a less powerful round than .30-06 hit the back of his head near the base of his skull, through his hair, took out neck bones and exited where we saw a hole appear.
I don't know where it came from. Any shooter seems unlikely with that tent up. Even Ian Fleming talked about guns hidden in cameras, and that was a long time ago. I have no doubt they exist. That camera behind the man which was hastily removed looks more and more suspect to me all the time. The angle seems approximately right; anything more than approximately doesn't count because bullets are known to deflect. None of this can be proven with anything I've seen. There was footage taken with that thing in view when he was shot. I see more than one person filming in the right position to catch that view. But we aren't being shown that footage, or at least I haven't found any of it.
I don't know what happened but I know what didn't happen. One or two of his neck vertebrae did not stop a .30-06 round. The official story is garbage, and this guy (which one is he? Martensen?) didn't do it any favors.