I noticed it too, it's definitely the studio version mixed with what they're playing because as you say Steve's drums seem to be live and Bernard's live vocal goes out of tune (frequently). Or maybe the actual performance was so crap they not-so-subtley dubbed it on in post-production?
Even Hooky's bass sounds like it's just the studio version being playing which is slightly ironic in lieu of recent *cough* accusations
either that or he's playing it completely and utterly note/rhythm perfect.
It's a weird performance all round that 1963... Dream Attack from the same show seems to be completely live by comparison but the sound of the recording is really muddy & shite.
Anyone else shed any light? Tim?