Like the other poster pointed out, it seems they were unarmed. Off-duty cops are instructed to carry everywhere except where they drink, it seems.
I strongly suspect that is the work of risk management types at the insurance carrier for the municipality that employs them.
When I used to give classes to new agents, my comment was to avoid mixing any 2 of the three Bs as those were what would get you in trouble. Of course that was 40+ years ago. The 3 Bs were Bullets, Booze, and Bimbos.
Today of course that would be non PC. Today has the specter of having yourself sued out of existence if you try to do the right thing and make a slim mistake or worse prosecuted for manslaughter.
Seems like there is a trend these days that when forcing adherence to rules is good, like maybe not having a Secretary of State with classified data on an email server that is CC’ing the Chinese on everything, the rules are totally flexible, and can be ignored entirely. But on a small thing like a Cop shooting a mass shooter after he has had two beers, the rules are totally inviolable, and people must be hung if anyone breaks them.
It is a very strange period, where every bit of common sense and goodness seems actively opposed by the forces behind society.