I hope most people in the CR don’t get offended so easily. This is an anonymous forum after all, and I hope we’re not all kids.
For children, peer pressure from fellow classmates is everything, and being embarrassed in front of everybody is akin to taking their life. This Rebbe literally saved this boy’s life by doing damage control and returning his self worth to him. Looking at it from this perspective eating Chalav Stam is similar to a Hatzalah member driving to a call on Shabbos – if he’s so makpid on Chalov Yisroel.