What to say to someone who feeds your puppy a Greggs' sausage roll?

[Asinine]

He was off lead and a workman just gave him half of his sausage roll. I was too far away to object while he was doing it, and didn't approach him after as I thought i might just get abuse. Pup is only 12 weeks and was sick later that day. He also went round town thinking that everyone with a Greggs' bag was going to feed him...

I suppose it wouldn't have happened if he'd been on lead, but he needs to have some freedom.

What would you have done? Or am I being too precious?

These zombie threads are a fascinating reminder of old usernames.

Also some problems are perennial {Dogs being fed sausage rolls!} so the zombie~ness doesn't really apply.

Someone googling 'Dog sick after eating sausage roll' will possibly see this in 2033
It has probably been happening since sausage rolls were first invented..

My dog ate breakfast this morning, and so far it hasn't made a 're appearance'- fingers crossed - if it does, I shall assume a tummy bug, not the sausage roll as cause, and only feed boiled chicken and rice.