I have never claimed any of the witnesses had an hallucination. Why would you imply I had? I simply point out the established fact that witnesses don't remember events perfectly. They tend to get some things wrong and some things right. I don't know why people had the same wrong misperception. I know people did have the same wrong perceptions and I can only speculate as to why and speculations don't establish anything. I don't know why some people reacted to the first shot and others did not. Clint Hill doesn't remember hearing the first shot but Glen Bennett, riding in the same car, clearly did hear it. So did JBC. So did Rosemary Willis.
Ok. How many things could have been reported as happening on the first shot?:
1. JFK could have continued smiling and waving to his right, which you say is what happened.
2. He could have turned to the left and waved.
3. He could have stopped waving but remained looking right.
4. He could have remained in his position and turned left but not waved.
5. He could have stopped waving and turned forward but not moved left.
6. He could have moved to his left but continued waving to his right.
7. He could have moved left and turned to his left but not leaned forward.
8. Or he could have stopped waving, turned forward and moved to his left and leaned forward, which is consistent with what 24 witnesses said happened.
Those are just 8 of the possibilities. No. 1 - is what you say occurred after the first shot. Not a single witness reported seeing this. Nos. 2-7 are not consistent with anything seen in the zfilm. Not a single witness reported seeing nos. 1 through 7. No. 8 is exactly what occurred in the zfilm after z224 and is not inconsistent what appears to be starting to happen after z193. At least 24 witnesses reported seeing something that is consistent with no. 8 and is inconsistent with no.s 1 through 7.
You say that the witnesses who observed something consistent with no. 8 were wrong. That means they made errors that just happened to coincide with what actually happened but did not occur on the first "horrible ear-shattering noise". The number of ways that a witness could have reported what they saw wrong would be at least 7 out of 8 (there are many other possible ways of being wrong). The chance that one witness would incorrectly report the no. 8 that didn't happen is at most, then, 1/8. The probability that
all 24 would report something consistent only with no. 8 would be 1/8
24=2 x 10
-22. That is a probability that it would never happen in the lifetime of the Universe.
If you want to believe that all 24 were wrong, my question would be: in what universe?
Now, you will come back and say that there are only two possibilities 1 and 8 and that the 24 witnesses were mistaken because they confused the second shot with the first shot or didn't hear the first "ear shattering noise". Let's assume that the chance of that happening is 50% - I would say it is much less but I am feeling generous. (And we will leave aside the question why they would be wrong in all mistaking the first for the second shot but not all wrong in observing what else occurred). That would mean that the chance that all 24 witnesses would make the same error and none get it correct would be 1/2
24=6x10
-8 or about 1 in 17 million. At least that is still something that might happen in this universe. Just not likely to have ever happened in human history.