I can't comment on the BHX closure, but this thread reminds me of a train derailment near Glasgow several years ago.
Several hundred pax were detained on the train for many hours afterwards. The police insisted that every passenger be interviewed, despite the fact that every account was the same. Pax were forbidden to disembark, regardless of grounds, and threatened with arrest if they tried. The driver, badly shaken, was also mistreated.
Police officers do a tough job and normally have my full support. But the responses to some incidents shows ignorance and bloody-mindedness born of poor accountability, especially in the higher ranks.