You can't even golf in New Haven from November through March (roughly speaking), and it's very unlikely that he'll spend his summers in New Haven, so you're talking about 4 months of golf at Yale vs. 9 at Stanford. As someone who spent seven years at Northern schools and watched his game deteriorate, I think the golf tips heavily toward Stanford .... and is there any argument that New Haven is nicer than Palo Alto?
As for the quality of the law schools, I have relatively strong views [which also happen to be reasonably well-informed, e.g., my wife is a YLS grad], but I don't want to pontificate on here, so shoot me an IM if you're interested in them!
Even if he doesn't get in either, he'll still be just fine.