Some of the witnesses to the after - missile - impact - flight - trajectories of the 747 airframe (that's plural, because there are a series of them, connected end-to-end as the remaining aircraft movement was uncontrolled) ... do not provide enough of a description of the vertical rise of a missile launch; they only cover the possible arch of a missile.
If they were northeast of TWA 800's location, the "flight" of the stricken aircraft could have appeared to be a rising, depending upon when they were looking at it, some of them would have seen an "orange" -like something, arching up, trailing white smoke, and then down (paraphrasing). The aircraft has already had its first explosion(s), thus the trails behind the "orange."
Even setting aside those witnesses, there are definitely plenty of witnesses who do describe a missile launch: the near vertical rise, etc. Some of these witnesses, depending upon their distance to the launch, detected literally the telltale "squiggle" of smoke from the missile's exhaust; while others of them might not have detected that "squiggle."
What a person would see, what they could see, what registers of what they would see, and what registers of what they could see, and why things register or do not, are all to be looked for in their statements and their backgrounds.
I would give Maj. Meyer much credit; not because of his past in terms of his service to our country, but because of this:
How a witness responds, is not only by what they are watching, yet it is also by what is in their registers already, and what such information triggers as the forms of their response.
Maj. Meyer's remarks do respond to his registers, though portions of his description are about an "arching" but no vertical launching.
What get's your attention is not what you first report, on many occasions of watching something happening at high speed. In fact, quite often, some thing "out of the ordinary" occurs to trigger your reflexes to "swing around" and "take notice."
We have, as humans, various recorder systems. That triggering event, registers, but is not so easy to recall --- that ability varies from person to person. The "start the tape" portion tends to be filled with description and is substantially reported over a series of interviews, as well as challenged.
Yet there is much value in the "trigger."
Maj. Meyer is a worthy witness, and there is a good probability that the in-shore missile's launch "got his attention." His time away from the combat theatre, would have helped to stall his "start tape" because his having "been there, done that" would challenge "the here and now."
For example, many men have difficulty with pistol target shooting, at the start, while women are better shots at the start. The women are perhaps more nervous, but they have not a lot of pre-conceived notions about the sense of the pistol; they react actually, somewhat more naturally. While the men tend to over-control; they have more baggage in the registers which comes to bear.
Maj. Meyer had to sort out the conflict of, "that's a launch," as such registered many times in Southeast Asia ... versus "what is going on here." There's a delay, as things get sorted out, before "start the tape" is a command finally issued, and so he records. His memories of Vietnam overcontrolled the present, long enough to delay the "tape start" until after the missile had begun to "arch over" on high.
Furthermore, his description of the first explosive signatures in the air, were literally "dead on." He describes aerial bursts, "hard," high-velocity type explosions which are typical for warheads.
Those remarks are his first, regarding any explosions --- it is not until later that he remarks about the fireball.
I believe he saw the in-shore missile launch. It brough back quite alot from his registers, and that required some fast sorting of the material, before he got things under control. Notably, being the veteran that he is, he still managed to comport himself to the emergency and usher the HH-60 out to the pending crash scene.
They arrived their rapidly enough to encounter still-descending debris, and they so-warned a nearby C-130 flight's crew, which then held off for a short while.