For his own halacha decisions - thats his issue. Not yours.
After you get over that, it's just business decisions after that, and he decided that it was a good one. Again, his decision, not yours.
What's so difficult?
And finally, if i was making a music video, should i not hire him because of this video? Guys, get over it. (And if you don't want to hire him anymore, go ahead.)