Logic Pro 9 disc filesize question

Colleague sent me a session fileset derived from his PT session and the files on disc are all slightly bigger than the originals... and slightly stretched.

( it's taken 3 days to troubleshoot the discrepancy)

How might this have happened?

turns out he sent me the wrong fileset, and now we have the right one we still can't match up audio and MIDI but that's being investigated here, so please move along, there's nothing to see here