You don't get out much anymore do you, Crab?
In this particular event....a Watch Standers with a firearm would have both help prevent it from happening at all as well as putting an immediate end to it.
Perhaps we do a better job of firearms training in our forces than does the RAF.
You may have seen reference to NCIS in news reports....the Navy's equivalent to the FBI (but with higher standards as of late)....at our HQ in Suitland Maryland....we had two Special Agents held hostage by a gunman INSIDE the HQ.
Management in a real fit of stupidity required all Agents to store their issued handguns in secure Pistol Lockers during work hours.
In those days....if I had my pants on....I was armed....no matter the policy but then I was not at HQ but out there amongst them!
Thus....dis-armed armed Police were victims of a Kidnapping inside the Head Quarters work spaces.
How do you think it would have turned out had the two and their colleagues been armed?