No worries there.
He seems to be a pretty smart little fellow. His eyes were probably bigger then his stomach, or so we say in Germany.
IF he is getting ready to shed, its better that he didn't eat. While some snakes have no problem to do both, shed and digestion, at the same time, I never even offer during shedding. Their bodies need extra fluid for the shedding process, but digestion does, too. With him just recovering, there is no need to put his body through double duty.
And maybe he really did have enough food already for now.
I take a refusal 100,000 times over a snake that will wolf it down, only to regurgitate it later on because it shouldn't really have eaten that meal for whatever reason. Regurgitation is really hard on a snake and can start a vicious cycle of problems. Much better for him to simply refuse to eat it, because he doesn't need to eat right now.
I think he is simply a smart little snake and realized that he shouldn't eat, once the thrill of the hunt was over !