When Rav Steinman visited America years ago, he had a bachur milk the cow in the farm and bring the milk over directly in a pot that he was watching the entire time.
I had a relative of my mother’s who used to work as a chalav yisroel mashgiach in the 50’s. He used to supervise the milking and sit on the trucks to the milk silo . At the time, there were 2 big cholov yisroel firms, and people who held of one hashgacha didn’t hold of the other. The interesting thing is that both companies stored their milk IN THE SAME MILK SILO! They just kept track of who put how many gallons in.
Rav Hershel Shachter holds that ALL milk is treif. Good thing Rabbi Belsky disagrees.