I watched it, and saw nothing wrong. When I was at that age, I saw MUCH worse thing. At the age of 11-13, my classmates were already talking about sex. Mind you this was a private school. But guess what, nothing ever came out it. I honestly started watching porn at the age of 10 because my friends got me into it. BUT, it didn't affect me, I didn't become a sex freak, I didn't have sex when I was 13.
It all comes down to self-will. If you teach your kids properly about self-will, and having an internal locus of control, you can expose them to anything, and it won't influence their lifestyle.
Another example, I practice boxing, and martial arts, couple times a week, and feel very confident in my abilities. BUT, I have never fought, or sparked a fight. Nothing is stopping me from confronting a classmate and fighting him, and winning. But self-will stops that.
Instead of focusing so much effort and time on shielding your children, spend time on developing self-will inside them. That will last a lot longer than temp shielding.