May I interject?
One, the Glock system IS precharged before firing, otherwise there would never be a beed to press the trigger to disasseble. The striker is partially cocked until the trigger cocks it fully and releases it, see attached video. That is explained about the 1.58 minute mark.
https://youtu.be/yRJI3QpJGw8Second, i hated stroker fire guns from the get go, listened to every horror story, saw every video...and then the Dept said congrats - you have to carry a Glock! So, I learned. The one single BIGGEST reason I saw for a Glock or any other striker fired pistol to negligently discharge in the holster was an obstruction in the trigger guard, nothing else. One was in a vehicle because a soft old leather rig got so "floppy" that part of the holster itself inserted into the trigger guard and fired the weapon while reholstering. The takeaway is clear - the fast one handed no-look reholstering taught in many classes are NOT what you need with striker fired pistol and any holster that might have caught part of your covering garment while reholstering. Even if carrying openly with no covering garment - look anyway. If you can't take your eyes off something long enough to look, you might need to keep that sidearm at the low ready, just in case. Also, open trigger guard rigs are NOT good for striker fired pistols. Bad juju as the old saying goes.
Here is my EDC, a CZ P-10C, (first gen with updated slide), in a High Noon Stingray OWB rig.
When unholstering, the standard training I received all these years of "
booger hook off the bang switch until go time" keeps me from a premature ejection...but reholstering, I take my time and make sure any covering garment, (I don't carry openly unless in uniform), is clear before sliding the weapon in to the holster. Period. There is no other safe way to do this, no matter the sidearm - a P-01 could have the exact same thing happen if an object was in the way, and the carrier was paying zero attention. Admittedly, the person involved would have to be practically catatonic to NOT notice there was a problem before the sidearm discharged, but theoretically any firearm without a positive manual safety in the on position could have exactly this type of negligent discharge.
Now, doe this mean I think everyone should carry a striker fired pistol and that anyone who doesn't is somehow undertrained? hardly - I carried hammer fired for decades, and would do so again in a heartbeat. I just found my perfect fit with the P-10 series pistols, (to nobodys greater shock than me - even CZ-USA was surprised), and I take the time needed to be completely safe.
Yes, I do carry IWB occasionally, in a High Noon Close Encounter, (made for a P-09, actually fits the P-10C perfectly), and I follow the same drill - watch what I am doing and clear all covering garments away completely. I take longer getting my pants up in a public restroom, but I don't leave a smoking toilet behind. Unless it's Taco Bell, then all bets are off...