Is it OK to look at your holster while re-holstering? Some would say no, others would say yes. This quick video presents one of the arguments for glancing down at the holster. Obviously, I was unable to cover every possible scenario in a video that is under 2 minutes in length. The context here is the defensive shooting where the armed citizen is likely carrying inside the waist band with clothing covering the holster. The law enforcement officer who is in contact with an individual or about to put the handgun away to restrain a suspect may not want to look down at his or her holster while putting the gun away. That officer is likely to have the holster on a duty belt and not IWB with clothing over it.
When an act can be performed fast and in a safe and secure manner by using the sense that provides the best information for decision making, use that sense.
Additionally, one should have the skills and techniques to safely re-holster into an IWB holster with clothing over it for those situations where taking eyes off of a problem may not be tactically sound.