1. The Biggest Hole is the Bronson film. It shows, that at the time of the headshot, the AR-15 was not pointed at the President. Indeed, at that time, the Secret Service agent had not even stood up and held up the AR-15 rifle.
2. The implausibility of a theory, that a Secret Service Agent, actually fired a shot and no one saw it or recorded it on film.
3. The implausibility of a theory, that a Secret Service Agent, accidently fired a shot, and by random luck, even though he was about 20 feet away, the shot struck the President in the head. The odds of this are less than one in ten thousand. The surface area of a sphere with a radius of 20 feet is 4 * PI * 20**2 or about 5,000 square feet. The ?Target size is approximately a circle with a radius of 4 inches which is PI* .33**2 or about 0.35 feet, giving us odds of about 14,400 to one.
The Donahue Theory has about as many severe problems as any theory I have ever heard of. Max Holland?s ?The Lost Bullet? theory seems rock solid ? in comparison.