I had hoped that Corbyn was at least referring to Menezes-type incidents, where the police clearly acted rashly with a tragic and avoidable loss of life. Apparently he meant something closer to the police attempt to free Bataclan on Friday. In the end over 80 people died there and I'm not sure it's clear yet what the order of events was, but my understanding of eyewitness accounts is that it wasn't a hostage situation but a slaughterhouse. The Police couldn't have moved in too soon, and couldn't have tried to shoot the terrorists dead too soon.
Our security services have to be given the ability to shoot terrorists dead if it's deemed necessary. That comes with the usual caveats -- last resort, public safety is paramount, etc. -- but it must be an option. Corbyn is wrong. Wrong, wrong, wrong.