Those horses' markings are very characteristic of the Sabino1 gene, which causes loud white facial & leg markings. That is why the markings seem to be genetic, because they are caused by that gene. In horses who don't carry the gene, you can increase the chance of producing a horse with more white by breeding to horses that have a lot of white, but there is no guarantee that the resulting foal will inherit the same "white factor".
White markings ARE gebetic and passed on as such, but there is no way to gaurentee where they will go on the foal, if at all. Sounds like the stallion has sabino or splash, which both like leg and face white. But no gaurentees the foal would get sabino or splash, and if it did, could be as simple as a star. There's also the possibility the mare has a white supressor, which further decreases the chance the foal will have white. I agree, if someone wants a specific color/marking, it's best to go buy one.
Your friend has good taste in horses! :) Unfortunately markings aren't predictable. (A few years ago a mare I bought was in foal. She was a dun with a swirly star and a partial white right fore coronet. Her baby was IDENTICAL! Same swirly star--not just a regular star--and the same partial coronet marking as her dam on the same foot. Total fluke. But it certainly was neat to have twins in the pasture!) And a Palomino isn't guaranteed when you breed two Palominos either, unfortunately. I'd start shopping--I love horse shopping! :)