I honestly don't think they were stupid enough to think they could escape the blasts set off underground in the Tube.
This is cool. This disinformation spread by the MSM will scare future suicide bombers away from "practice runs" and so forth, depriving the muslim masterminds of a source of recruits. Finally the MSM is using its lying ways to help the West.
Maybe they bought round trip tickets because that's what they always did. People are creatures of habit.
Personally I don't care if they were duped or not. They're dead now and answering to a Higher Court where claiming to be a victim of American Imperialism won't get them out of jail free.
The terrorists met in Luton which is where they parked their car, then caught the train into London together. There is an airport in Luton and although they boarded the train at the town station rather than the airport it is a station where a mixed group of youngish people with backpacks buying one way tickets would not have caused any surprise at all.