I admit, I don’t understand the concern about the emergency communications - The advice from the Met makes perfect sense. Untrained people ‘having a go’ generally leave nice wet puddles of blood and/or cause suicide bombers to detonate their device before anyone can get away, so it’s not going to be advice from the Police to ‘have a go’.
The armed police are eight minutes away, but that clock only starts ticking once someone reports the incident, so they want someone to be able to report it. Then they don’t want people hurt, and finally they want the target zone as clear as possible for when that clock reaches zero and the trained response unit ends the threat.
“Get out of there, hide, and contact us” seems to cover it pretty well.
