I do think that procedures need to be tightened to prevent a similar thing ever happening again. However, I do think the police are on a hiding to nothing. If JCdM had been a terrorist and there had been a tragedy on the underground because the police didn't act quickly enough, they would have been hung from the rafters. 7/7 spooked everyone, particularly the security forces, making them much more likely to act quickly and perhaps without sufficient thought - and that is where the changes have to be made.
It is clear that certain established procedures were not followed (the fact that the observer had gone for a pee or something and therefore couldn't confirm JCdM's identity but action took place anyway) and I do think someone has to take responsibility for that. Not sure that the family will get much relief from this inquiry. Nothing will bring their loved one back. Awful for them.