I'm going to quote from this article:
The Warren Report concluded that Oswald had fired all three shots from a window on the sixth floor of the Texas School Book Depository, where he worked.*But the case was far from closed. A man named Abraham Zapruder, one of thousands of people standing along the motorcade route that day in Dallas, captured the shootings on his 8mm home-movie camera. At 26 seconds and 486 frames, it would come to be the most thoroughly examined snuff film in history—and a prime piece of evidence for the Warren Commission and the subsequent “conspiracy buffs.”
At first, it was assumed that Kennedy and Connally had been hit by separate bullets. But the Zapruder film threw a wrench in that notion. The Warren Commission’s analysts concluded that JFK was shot sometime between Frames 210 and 225 (a street billboard blocked Zapruder’s view at the crucial moment), while Connally was hit no later than Frame 240. In other words, the two men were hit no more than 30 frames apart. However, FBI tests revealed that Oswald’s rifle could be fired no faster than once every 2.25 seconds—which, on Zapruder’s camera, translated, to 40 or 41 frames. In short, there wasn’t enough time for Oswald to fire one bullet at Kennedy, then another at Connally.
The inference was inescapable. Either there were at least two gunmen—or Kennedy and Connally were hit by the same bullet. The Warren Report argued the latter. The “single-bullet theory,” as it was called, set off a controversy even among the commissioners. Three of them didn’t buy it.
That section of the Warren Report drew the most biting attacks. Critics drew diagrams tracing the absurd path that a bullet would have had to travel—a midair turn to the right, followed by a squiggly one to the left—in order to rip through Kennedy’s neck, then into Connally’s ribs and wrist.
Before proceeding, let's pause to consider this. It appears to be a mathematical impossibility that a single gunman was responsible for shooting both men. The rifle can only fire so fast. And there's only so much time between frames. Plus the trajectory of a bullet from a 6th floor perch. It wasn't mathematically possible for one shooter to get off three rounds in that interval.
So the evidence seems to contradict the lone gunman theory. And not just any kind of evidence, but evidence of a very stringent kind. Mathematical rigor.
Then, in November 2003, on the murder’s 40th anniversary, I watched an ABC News documentary called The Kennedy Assassination: Beyond Conspiracy. In one segment, the producers showed the actual car in which the president and the others had been riding that day. One feature of the car, which I’d never heard or read about before, made my jaw literally drop. The back seat, where JFK rode, was three inches higher than the front seat, where Connally rode. Once that adjustment was made, the line from Oswald’s rifle to Kennedy’s upper back to Connally’s ribcage and wrist appeared absolutely straight. There was no need for a magic bullet.
Notice how that one additional piece of evidence might suddenly resolve what appeared to be an incontrovertible contradiction. Turns out that one bullet could do the work of two.
Now, I'm not vouching for this explanation. I"m not a JFK conspiracy buff. For all I know, there may be criticisms of this explanation.
I just use this to illustrate a point. Consider in principle how a single piece of missing evidence can resolve what seems to be an irrefutable contradiction. And think about that when unbelievers confidently allege a contradiction in Scripture.