I'm not sure it was 100% clear cut. He had his hands up there as defenders often do to demonstrate to the ref that he wasn't fouling his opponent. So it certainly wasn't intentional handball. And whilst refs are directed to penalise handballs when the hand is in an "unnatural" position, I interpret that to mean when hands are positioned deliberately so that the ball may hit them. Which I don't think applies to Boetang.