My grandfather carried for 66 years in the pocket with out a holster and never had any problems. He said he did not like how the holsters felt. He has now passed so I guess it is possible to not use a holster and never have an accident.
I carried for 11 years with out a holster and no incidents. It wasn't until I got a holster (as advised by this forum and my wife) that I ever had a problem. The stiff leather did not allow my shirt to move away from the gun when re-holstering it and the gun went off, Fortunately I was on my own land and no one got hurt (other than my pride).
I have switched holsters
Shot placement is everything! I would rather take a round of 50BMG to the foot than a 22short to the base of the skull.
all 25 of my guns are 45/70 govt, 357 mag, 22 or 12 ga... I believe in keeping it simple