mesorah 123 -“He didnt double check the milk and accidently used a private bottle of instead don the Yeshiva’s cholov Yisroel milk.”
This is the problem with trying to prove something from a Maaseh, instead of the Psak that he wrote. Maybe he vomited because it was s/o elses’ bottle of Cholov, instead of the Yeshivas'(stealing)!