Okay, a couple of problems here. As far as shooting at the pelvic girdle, while it may drop the threat to the ground, it does nothing to eliminate the threats ability to continue to shoot at you which should be your #1 goal. Knocking out the hydraulics or central nervous system is the only way to make sure that you eliminate a threat.
As far as the "technique" of two shots to the pelvis and then continue to fire as you draw the gun upward...this is an improper technique of drawing from a holster. A handgun should be drawn straight up from the holster, rotated 90 degrees and pushed forward into the firing position. The problem with drawing and sweeping the gun up is that if you always do that you may find yourself in a situation where the threat can block your arms as they raise up from a low position. By keeping your weapon close to your body, rotating and pushing out you can make viable hits on your threat with the gun close to your body until it is pushed all the way out; you are always in a good firing position to make good hits. Just my 2 cents.