An uneven hinge can be viewed as glass half full glass half empty, extra or deficient. August views it as making one side deficient to have less pulling influence on the trajectory because he literally removes material from that side. Other oddball hinges leave extra material in the face configuration to have more influence. The physics as I see them is each side of the hinge makes a resisting torque to the spar fell kind of like a guy line offset to the side of the trunk diameter. If one guy line pulls weaker then the other the fell goes off the center line. To get perspective on the size of torque note that the tree won't even go over until the hinge is down to the equivalent of a 2x12 or 3x12 oak plank. Then figure how much force it would take to snap off said plank say extended 6 feet - sizeable. Neglecting the progressive weakening as the hinge fiber fails during the trunk' down trajectory, that's considerable steering force.
That brings up that as the spar gains speed you need more oomph to deflect it. Right at about the time a fair proportion of your hinge fibers have failed. So steering with hinge torque is more effective early in the fell trajectory.
That being said I once had a small live topped conifer go over unintentionally a bit off center due to uneven hinge but the eye opener was that the wood was so chewy the hinge held the entire spar off the ground horizontal. Go figure.