I should think - and police blogs seem to confirm this - that it was the fast-tracking which caused the problem. Cops started to be promoted without being tempered by life on the streets. They now reach command positions without command character, and too many have been described as politicians in uniform.
Come to think of it, much the same could be said of other parts of British leadership, scientific, political and administrative.
A telling point of the Enquiry into what happened was the account of the Control Room all shouting at one another, and into the radio, as the police on the ground moved. Had you had that sort of thing in Ireland, the result would have been bloody shambles, or paralysis.
One has sympathy for the cops on the spot for that reason. But this is modified by the knowledge that their training is poor. In the shooting clubs we used to see this, and the SAS, who try to sharpen them up, tend to despair.
My point is that if you are absolutely sure you are good, you can afford to take that extra second to think before opening fire, and have the confidence not to shoot if it is clear the target is in fact harmless. Maybe even that would not have saved young Menenes, but he should have had more of a chance than he did.