The following is an excerpt from an interview between Sir Ian Blair and Steve Donovan, a journalist with an ounce of brain, some dignity, and capable of independent thought. As you have probably guessed, it's completely fictional.
* Steve: So, what's this "shoot-to-kill" policy you've come up with?
* Ian: First of all, please don't call it that. It's not like we go around London trying to kill people.
* Steve: But that's exactly what happened the one and only time the police have made use of that policy...
* Ian: The tube shooting is a distraction that should not overshadow the deaths of 52 victims of the London bombers.
* Steve: What are you suggesting? That 52 lives are "more priceless" than one? Or maybe you mean that the police have not only wasted an innocent life, but also failed to save 52 more? If you like statistics, then how about this: the shoot-to-kill policy has saved ZERO lives so far, and wasted an innocent one by mistake. This is a policy with 100% failure rate. One cock-up out of one time the policy has been put to use.
* Ian: But wait, if Mr. de Menezes had been a terrorist, surely this policy would have saved lives...
* Steve: As it turns out, not even that. If, as it's likely to be the case from now on, the bombs are triggered by a timer, a remote-control (e.g. mobile phone, like in Madrid) or a dead-man switch (a switch that triggers when it's released, as opposed to when it's pushed, think hand grenade), the policy can't do any good, so we are only left with its risks.
* Ian: Oh but come on, this has just been an unfortunate accident...
* Steve: If this policy does make us safer, it must have been a hell of a fucking accident if it failed the first time it has been tested. Remember: 100% failure rate. I can imagine thousands of scenarios where this policy would have lead to an unlawful death, be it of an innocent man behaving "suspiciously" (or simply cacthing a train as in this case), or of a genuine suspect not posing a threat to the public, in which case it would be a summary execution without trial.
* Ian: You convinced me, I'm a complete idiot and I should resign.