I carry a firearm that I have access to - we have weapons retention training, and while some retention holsters are fine, the Dept does not pay for them.
Situational awareness is 99% of weapons retention. Also, we don't generally go armed in the GENERAL public without at least two, if not three of us at a time.
I've carried openly in AZ for years with non retention holsters, (since...1985, IIRC), and haven't had any issues yet.
Generally I do carry concealed off duty, I'll concede that - with an open top level 0 rig.
But to the REAL crux of the your question - where I'm wearing THIS rig at work, nobody can get to me. Period.