To the best of my knowledge you can't make them lose a foot without causing growth problems (two or more leaders). You can slow their growth by removing part (not all) of the new candle so that instead of adding 5 inches, it only adds 2 inches, for instance. If you remove the entire top or branch end, most pines will respond by the several branches at the next whirl back all trying to take over the leader position, resulting in weak, multiple branches. It's a hormone thing - the leader (end growing branch or top) sends out a hormone that keeps it dominant, and if totally removed, there's a growth free-for-all. I think what your friend did was shear (cut off the outside) as opposed to what I consider pruning (cut individual branches to improve shape or remove problem areas.) See the link below for information on candling vs hedge trimming or shearing.

Scots pines are genetically inclined to be trees, not bushes unless he bought a special grafted dwarf variety, which I can't imagine since he has 30 of them and grafted plants are expensive. In my opinion, pines look best if left to grow naturally, so he may want to think about starting something new that will stay closer to his desired size and then when they have grown some, remove the Scots pines. Candling 30 Scots pines annually sounds like a LOT of sticky work.

You will probably get better input than my limited knowledge if you ask over at the conifer forum as my pines are left to their own devices.
http://forums.gardenweb.com/forums/conif/

Here is a link that might be useful: candling pines and restricting growth

Thanks for the info. Looks like what he did was to chop the top and side to a square this past fall, probably removed over a foot on the top. Not real pruning. So it looks sparse and boxy right now. Not much new growth either.

But I do notice a few that must have been cut very low a few years ago and they do look better. These are very low, maybe 2 feet high with good looking growth and needles.