Tomás
Thanks. If anything, the video is perhaps too short. There is so much to the topic of a well-executed fret job. I could not go into much detail because the person shooting the video requested short clips for their instructional (ehow) website.
Yes, the 12th fret and body should be aligning. Small deviations may be okay, but anything larger will surely be a confusing arrangement for the guitarist, no? In that video, this guitar was shot, and here's the photo where you can see 12th fret position.
Best regards,