did the bombers catch the 7.24 train at luton?

financialoutrage.org.uk has done some work on the luton to kingscross trains on 7/7.

i had previously been working off timetables - but these people got the actual details of train times on that day - including what time each train left luton, and what time it arrived at kingscross.

the press has been claiming that the bombers had caught the 7.40am train - but as it happens, that train was actually cancelled. given all of the delays and things, the only train they could have caught was the 7.24 train which apparently left luton on time (altho the site doesnt demonstrate that it did), and then lost 20mins in transit to arrive at kingscross at 8.20.

the cctv footage of them entering luton was taken at 7.22 - the site posits that there is no way there is sufficient time to get from where the picture was taken to the platform in those 2 minutes - let alone buy tickets.

it is possible that they had previously bought tickets - the police seemed sure that the bombers bought return tickets, although we were never told how they know that - did they match up the transactions with cctv footage at the ticket desk? were they bought with a credit card? were all the tickets purchased in one transaction or did each bomber buy their tickets separately? it'd be nice to know when that transaction(s) took place.

more confusion