Does the dude with no legs really have no legs?

No, the actor has legs. The amputee was played by Paul Brannigan who was in Ken Loach's "The Angels' Share" and in that film he wears a kilt...
http://www.imdb.com/media/rm2367922176/tt1924394?ref_=tt_ov_i

It was good green screen!

Its that man again!!

Method actor, had them cut off for the role.