Sorry to hear you had that trouble on Stack Overflow -- I assume it was SO, anyway; most of the Emacs questions tend to live there.
I doubt you care at this point, but for others who might, it's generally a better alternative for a new user to comment with the correction, than to try to edit; comments are globally visible no matter who makes them, and a comment pointing out an error like that one is very likely to result in its being edited into the answer by someone who does have the reputation score necessary to do so. Even if it doesn't, someone who tries to use code from the answer, and finds it does not work, will be able to read the commentary and find out why not and how to fix it.
As for the edit reject reason -- well, all I can say is that idiots get everywhere, Stack Exchange sites not excepted. For whatever it's worth to anyone, I've found that sort of obstreperous idiocy much less common on most SE sites (again, English Language & Usage excepted!) than in, for example, Wikipedia.
Comments are only available at 50 reputation points (or some number requiring a large number of previous reputation building actions), which a new user wouldn't have.
Are they? It's been long enough since I started that I'd forgotten. Still, 50 points is 5 upvotes, which is not difficult to attain quite quickly -- I earned >400 rep in my first two days with an account on Super User, and while that's not typical and took some effort on my part to achieve, a mere 50 points shouldn't be all that hard to manage by comparison.
I doubt you care at this point, but for others who might, it's generally a better alternative for a new user to comment with the correction, than to try to edit; comments are globally visible no matter who makes them, and a comment pointing out an error like that one is very likely to result in its being edited into the answer by someone who does have the reputation score necessary to do so. Even if it doesn't, someone who tries to use code from the answer, and finds it does not work, will be able to read the commentary and find out why not and how to fix it.
As for the edit reject reason -- well, all I can say is that idiots get everywhere, Stack Exchange sites not excepted. For whatever it's worth to anyone, I've found that sort of obstreperous idiocy much less common on most SE sites (again, English Language & Usage excepted!) than in, for example, Wikipedia.