It should be remembered that a battle sight zero is not a precision thing.
It is an idea that the military and shooters use to limit the importance of accurate range estimation when shooting at people. For example: a 50 yard zero, or 50/200 BSZ will keep the trajectory of 5.56 and 7.62 within 3 or so inches from the muzzle to 250 or so, and within 6" to 300. This is pretty much true from Mk18 to M16A4, M193 to M855A1, and iron sights to an Acro on a 2.6 Unity mount. It'll let you hit the "C" zone without trying to guess range. Just hold COM and send it. Also worth noting that this concept is designed for 3 MOA guns shooting 3-4MOA ammo, and (optimistically) 3 MOA shooters. The Marines are using a 36/300 BSZ these days, because they still like to pretend they shoot to 400M on a battlefield.
IMNSHO if you are running ballistics calculators and checking height over bore of your optic, you don't need a BSZ. You are branched out into a different kind of shooting, which is fine, but probably the BSZ isn't for you. At that point, your ability to range targets matters, and your zero doesn't really, because you are probably either dialing range, or holding in a reticle, the two things a BSZ was specifically invented to avoid.
As far as the Trump shooter, I know nothing about his shooting ability, or how much his MKUltra handler taught him, but we know he had a range finder, and had concerned himself with ranging his shot. Assuming a functional Google, it's probably safe to assume that he had zeroed for that range, or [thought he]* knew his holds, so conjecture of one of the popular BSZ's is probably just navel gazing. If I knew I was taking that shot with an unmagnified red dot, I'd have zeroed for the known range myself and if I was using a 25YD range I'd have calculated the offset needed for my 130yd or whatever zero, but again, this kid's knowledge is still a mystery box.
*I say thought he knew, because there's been no mention of a chrono in his stuff, and that kind of "sniper" gear I think would be mentioned. If he was going by velocity data on the box of whatever he was shooting, he could be WAY off.