It is a very awkward hole. It's also confusing to discuss because they switch the nines for the tournament -- I will use the tournament numbering to describe it below.
Raynor's original routing had the 18th playing back down today's 10th fairway; the original 10th hole was along the beach, now occupied by some very expensive condos and the Kahala Hotel. [The 11th and 16th holes were originally along the beach as well.]
When the club decided to do those land deals and brought in RTJ, he used the old 18th fairway for the 10th, and moved the 18th hole further inland, so that it doglegs around the 10th. To prevent people taking liberties with the short-cut, there is a line of palm trees on the left 50-100 yards off the tee, kind of like the "wall" teams form for penalty shots in soccer -- you don't play too close to them for fear of hitting one and having no clear shot for your second.
Until last year, players might try to hook a tee shot to cut the corner, but no one ever tried to play down #10. I don't know if they lost a tree in the wrong spot, or if the players just hit it so high now they are confident in playing up over the trees -- it's been three years since my last visit. I think the internal o.b. is an appropriate solution. It might be the best result permanently, as well -- the trees have always been an awkward solution.