British intelligence is at least considering the questions raised in the article linked to in this previous post.
Regarding the July 7 attackers (not the subsequent ones):
They bought roundtrip train tickets and paid for long-term parking – two of the details that are prompting the intelligence community to question if the four London bombers intended to die.
Associated Press: Did London Bombers Know They Would Die?
Those who disagree with the ‘not suicide’ hypothesis suggest the bombers were being cautious to avoid suspicion.