I've still got my Ektelon D as a back up machine! Serious Workhorse! Yeah, they were stringing as a pair - looks like one guy weaving and clamping and the other guy tensioning. Not sure if that would make me any faster tho! Also, at the end the racquet was still on the table and the string ends not cut so I would guess that the time was for the racquet on the machine and doesn't include mounting etc. I think these days fastest stringer comps include cutting, mounting, stringing and removal from the machine?
I reckon with an aeropro or pure drive and a nice, easy weaving syn gut I could go to about 12 minutes for a quality job but normally average around 24!