My biggest gripe with Coderwall is that without comments, there's a lot of stolen content in addition to no way to correct someone when they're off about something or give them a better suggestion.
Coderwall does give you links to contact the author if you'd like to suggest something. His Twitter handle is on his profile page.
Correcting someone on Twitter draws a lot more attention to the conversation than necessary and, in my experience, people react more defensively because of it. I also don't think it makes for very good UX to have to go to an entirely different site to ask questions or get refined answers to posts, especially when those conversations are relevant to everyone else who reads it.