If he had a retention holster and if he had engaged the slide mounted safety the OP would not have posted about him.I am surprised that the discussion of whether the school resource officer was safely carrying deteriorated into a wide-ranging discussion of open carry in general.
Seems to me the sensible response is that the officer very much needed a better holster that offered some REAL retention of the pistol.
ALL the rest of the commentary in this thread IMHO, is just superfluous.
If I think an open top holster is dangerous, I may say so.
If I think using the third gen decocker is dangerous I may say so.
but when I say "why", that is when the fallacy shows.
What the resource officer was doing, assuming a properly fit holster, was unremarkably normal, or it ought to be.