The spot on the skin was identified by the autopsy doctors as a bullet hole. There is no evidence that the bullet hole moved. Unless there was a broad conspiracy involving at least all three autopsy doctors and the autopsy photographer plus some unidentified photo touch-up artist who had skills that were 50 years ahead of his peers, that photo tells you where the bullet entered JFK's back.
Which spot on the photo you are talking about did the autopsy doctors identify as a bullet hole and when?
Why would you call a conclusion based on actual evidence a conjecture?
Because it is. Just because somebody saw something sticking out of a window, it doesn't just follow that it was a rifle being discharged. None of them (except arguably Euins) saw a rifle being fired. You're just assuming that what they saw was a rifle that had been fired. But if you're going to take Euins' word for it, then you have to deal with the bald spot and the fact that he initially told a reporter that the shooter was black. Under your standard where a conclusion based on evidence is automatically "proof" you would have to concede that it's proven that Oswald was not holding the rifle in question.
But even without Euins, one could conclude from all the other evidence that rifle shots were fired from the SN. The evidence (not conjecture) is that a loud noise that many identified as a rifle shot preceded Cabell's observation of a pipe projecting from the SN window, and that 3 such loud sounds preceded Jackson's similar observation.
Ok, but that doesn't tell you where the loud sounds originated. It's just your assumption that the loud sounds must have originated from Mrs. Cabell's "projection". There's no evidence of that.
There was clear evidence that a bullet fired from the rifle found on the sixth floor fired one of the bullets that ended up in the President's car.
Unfortunately that doesn't tell you
when the fragments allegedly found in the President's car were fired. And like so much of the evidence in this case, there is no solid documented chain of custody for these fragments between their alleged discovery in the limo and Robert Frazier. Furthermore, Frazier took these mangled fragments and lined up the markings "in his mind" because they didn't line up under the microscope. There's nothing "clear" about any of it.
Norman heard what sounded to him like bullet shells hitting the floor after each loud sound. He heard what sounded like the a rifle bolt action after each of the three loud sounds.
Yes he did eventually say that. That raises lots of questions though like why didn't he hear the guy's necessary mad dash to the stairwell which would have been necessary had it been Oswald up there or why he and the others lollygagged looking out the western windows of the 5th floor in view of the staircase if they had any inkling of a shooter upstairs.
All three men heard the loud sounds and thought they were coming from the room directly above them.
To suggest that a conclusion based on this evidence is just a guess is preposterous.
I didn't say it was
just a guess, but it does have several built-in assumptions that are not evidence-based.