Much has been mulled over about Jeremy's " delay " over phone-calls but surely the most outstanding is the fact that nearly 3 hours were WASTED outside WHF instead of acting immediately where 4 lives were at stake. Was that not more important than having discussed Jeremy's " dilatory " attitude on not ringing 999 ? His was 10 minutes possibly wasted but 3 hours is/was worse for a team who would have been fully equipped to have dealt with the situation.
Jeremy's wasted minutes pales into insignificance or it should do against a professional team of men.
It's police procedure, they won't risk the lives of officers or hostages until they are as sure as they can be, that there is limited danger. If police go charging in, it could mean more victims on both sides. That's why they try to negotiate with the suspect, which is what they did. Unfortunately, the 'suspect' was already dead, along with everyone else and the culprit was leading them up the garden path and orchestrating proceedings.