I agree, your rosy is the shy type. (you'd know if he was a biter, LOL) Try later with tongs, but don't keep at it if it doesn't work...leave it & hope for the best...it might disappear by morning?
Your first plan for a yearling rosy was a much better choice...had you asked me first, I'd have suggested you wait until this one had eaten a few more times for the breeder, because 2 meals is better than nothing but not by a whole lot. Young rosies can be frustrating, especially without a source of live pinkies- and I know you thought you had it "covered". He's your snake now so all you can do now is think positive & keep trying...just like stubborn BPs, he should eventually decide to eat for you. I've raised LOTS of neonates & hatchlings over the years, of many kinds...some can really frustrate us but we also learn thru the process...you will too.Keep your motions subtle (when offering pinkie from tongs)...good luck! If he starts to take it, freeze in place until he has it down...motion by you can make him drop it & then refuse. No kidding...