Last things first: Dude, if you're going to ask your creator for a boon, which you know is going to fill him with absolute horror, doing so right after the "oh yeah, and I brutally murdered your totally innocent little brother, and feel no remorse about it, and pinned the deed on some innocent woman" is probably not the best way of going about it. Just sayin'.
Anywho. Yeah, could have said that nothing good would come of the whole "reveal to peasants" plan. Although I wonder why the health of the old man is so affected... was he upset by the whole melee right at his feet? Was he frightened when told of the Creature's appearance? I guess we'll never know.
Also, while my sympathies started out wholly with the Creature, the more he reacts horribly to things, the less sympathy I have. Oh, I'm still sympathetic to his plight, and still lay a ton of the fault at the feet of his creator, but dude. While reacting badly to everyone wanting you dead is understandable, a) it's still falling in the "reason, not an excuse" side of things, and more importantly b) taking out your anger on all the innocents involved is not cool! I mean, he gets snubbed by the peasant family, so he burns down the house that they're no longer living in and that belongs to someone else. He's upset with his treatment by the world in general and by his creator's rejection specifically, so he goes off and *murders his creator's innocent little brother*, and then pins the crime on some poor girl sleeping in a barn (who also is important to his creator, but he doesn't know that). Dude, WTF! Can you inherit schmuckitude from your creator even when you don't have his genes?
Anyhow, side notes: apparently despite their name, the Frankensteins are some of the French-speaking Swiss, which makes sense if they live in Geneva, which is part of the French section, according to Wiki Pete. But while we're on coincidences/contrivances, let's add to the count a) the fact that the monster just happens to bump into his creator's brother of all people, b) when he then pins his crime on some random person, it just happens to be another member of his creator's household, and c) the fact that in the middle of Germany, the bundle of books he happens to find also just happens to apparently be in French (since he mentions he doesn't speak the language of the country folk around the peasant house). I know that novels in general and especially the ones before our modern standards require some suspension of disbelief but... yeesh.
And for what it's worth, here is what Wiki Pete has to say about the term "syndic" that the boy uses, which was unfamiliar to me.
So anyhow. Yes, the monster killed the boy, and not even accidentally. And pinned the crime semi-knowingly on the other girl (knowingly in that he knew what he was doing, but yet he didn't know she was a part of his creator's household). Which makes my sympathy for him markedly less. And now his tale finishes, and we get to see Frankenstein's reaction to both the tale, and the creature's request for a mate. Can't wait!