“Back holsters are not nice - they are dangerous. Never, ever wear your gun on your back or behind the hip. This is not a comfort issue. I’m surprised anyone who has been around guns would say that it is acceptable when every expert will say that it is not.”
Define “expert”.
“Define “expert”.”
Not you, apparently.
Any expert with firearms will tell you that a holster that makes you point or sweep the muzzle of your weapon toward some part of your body is considered more dangerous than a holster that prevents this from occurring. Hip holsters are therefore preferred since you draw toward the ground and never point the wepon at a vital part of your body. Cross-draw and bandolier-style holsters also keep you from shooting yourself, but they also take more time to draw and force you to sweep your weapon laterally.
When drawing quickly, the back holster tends to make you point the muzzle of your weapon in against the side of your abdomen or hip. That is very, very bad. When drawing from many shoulder holsters, the muzzle must be swept past your arm, which is also not a good situation to be in. You can, however, move your arm up and out at 90 degrees from your body while drawing, but this is clumsy and unnatural. If wearing a jacket, it can sometimes cause the weapon to get caught up in the jacket itself. The shoulder holster also forces you to sweep the weapon laterally by as much as 180 degrees, which exposes anyone walking behind or beside you to a premature firing.
The only way to avoid these problems is through extensive training to learn not to engage the trigger until the weapon is pointed at the target. The other option is to never let yourself get into a situation where you have to rapidly draw, but in real life the situation cannot always be controlled by you.