Bottom line is she had her finger on the trigger. The gun is not the problem. Trigger mechanisms are just fine for preventing accidental fire.
Unless there is intent to fire a finger should NEVER be on a trigger. Total incompetence and lack of respect for the weapon.
Accidental discharge - maybe. Negligent discharge - definitely not.
Everyone "should" drive safely but cars are still made with bumpers, air bags, seat belts, crumple zones, collapsing steering columns, safety glass, anti-whiplash headrests, fuel and ignition cut-offs, etc.
A handgun owner would be well served with a handgun with a safety because there are Didn't Earn It (DEI) hires littering police departments all over the country.
2 trains of thought here, not getting into it except as follows:
When my Glock is in condition 0, I’d certainly advise an officer keen to remove it from the holster inside my waistband.
In this case he did NOT (body cam) and the officer clearly had her finger hooked on the trigger.
He played a role in his injury IMHO. Additionally, she may have demonstrated firearm incompetence, but I question the level of training she received. It should also be part of the larger investigation.