DaasYochid and Lior,
Wouldn’t the difference be between people who follow Rav Moshe Feinstein’s ruling that chalav stam certified by USDA in the U.S. is kosher, but it’s still good to be makpid on chalav Yisroel (thus they eat chalav Yisroel, but aren’t so concerned about the keilim) vs. people who don’t hold by Rav Feinstein regarding chalav stam (thus they would be concerned about keilim since they consider chalav stam to be non-kosher)?