I think taking the holster off is the only truly safe way.
Another safe way is to holster slowly and carefully, with full view that nothing is blocking the holster (IOW, it is clear of any obstruction, best seen by looking straight down into the AIWB holster); finger off the trigger. Or even better, if you have a hammer down DA gun, with your firing side thumb on the hammer to feel if the trigger is pulling the hammer back from an obstruction. Have the holster bottom tipped away from your body as you holster, so if there is a ND the bullet misses the body. Easy to do with AIWB.
Once properly holstered in a safe, fitted holster, the gun cannot go off.
So drawing becomes the next potential danger point. But the trigger cannot move backwards to fire the gun while the gun is being drawn. Only when the trigger clears the holster can a negligent shooter get his finger on the trigger before pointing toward the target and possibly ND the gun. That's a training/dry practice/timing issue which should be ingrained before carrying the gun with live rounds—in any carry position.
Follow these rules for any carry position and you will not shoot yourself. Skimp on training and practice, skimp on a substandard holster/belt/attachment rig; wear it in silly positions with no visibility for holstering and/or with the trigger unprotected, and you are not carrying safely.
If there are any reports of one using a modern/safe gun in a properly fitted/mounted holster AIWB shooting his privates or femoral, I haven't seen them. There may be a few where the one responsible did not follow safety rules, was ignorant, negligent, or whatever, but such folks are going to hurt themselves somehow someway any way. It's not the fault of the carry position.
I literally have six years under my belt AIWB, and I truly believe it is at least as safe, done properly, as any other carry position. It is not for everyone because people set up blocks in their minds and don't truly investigate and try things new to them to make their own decisions, instead deciding based on incorrect internet lore, improper assumptions, and fear.
Here's a recap (can't get to the original story) of an officer who while holstering shot himself in the buttocks and died. Does this one instance mean that no one can safely holster a gun where he might shoot his buttocks? No, it doesn't. It means this one person performed a negligent action and paid the ultimate price. Too bad, but there is more to the story as to how his negligence killed him. The same is true for Post #23, which also lack the link to the full article explaining what types of negligence contributed to this tragedy. Certainly practicing something new with a loaded gun rather than dry is a bad start.
