Mike Campbell wrote: "When I chase right angles, my dominant right eye is over the rib and the target is to the right of the barrel and I'm constantly looking to the right; my left eye is bringing up the rear and not really much involved in the shot. When the target angles left it's in my left field of view and during the swing the muzzle is constantly moving into that field. That encourages the left (weak) eye to take over, lock on the target and show me when I touch it....when in fact, I'm well ahead of it."
This is exactly what happens to me. I have used the Uni-Dot hooded fiber optic front bead for 10 years now but sometimes I still crossfire on hard left angles and don't remember seeing the green bead but instead I vaguely remember seeing the left side of the black tube. Phil Kiner says locking on the target with the wrong eye is the real problem and he recommends using the tape patch when the crossfire preventer is not enough to solve the problem.