Oh, hell no. I would be filing a grievance and demanding a meeting with the classroom teacher, the principal and the boy's parents. There's a history of the other kid bullying your son; he should not have the opportunity to approach your son in the crowded chaos of the lunchroom to further terrorize and intimidate him. It's unacceptable; if the school isn't responsive and can't keep that other kid away from your son, I'd be going to the school board, writing letters to the editor of the local paper, etc. until there was a satisfactory plan in place. I would also demand that the "referral" be expunged from his file/record.