What could the Security Services and Counter-Terrorism Teams done about it, to what extent were they know to the authorities, because I am sure if MI5 or Police had specific intelligence they would have acted on it and took the offenders into custody. I am known to Police in 2 North East Forces, but they don't keep tabs on me 24/7.
Now, as for people who seemingly did nothing to help, I would not have stepped, doing that is stupid, you may get a commendation, but it would your next of kin recieving it more than likely.
For punishments, I have quite extreme opinions, as seemed to happen in the early days of the Troubles anybody suspected of terrorism should be interned and brought before Diplock Courts with the death penalty being applied if the evidence and case against them is absolutely overwhelming and stacked against them...
That attack was not only an attack on the armed forces, it was an attack on the country, that to me is a crime against the state and should be dealt with very harshly, if harsh means death, then so be it, there should be no mercy in cases like this, you take someone's most basic human rights, the right to Life, then you don't deserve any rights in return...