Did you file a support ticket for this? It sounds like an unrelated problem. We can investigate if you let us know what repo is causing the problem. Visit http://support.github.com or email support@github.com.
For what it's worth, I was pulling & pushing just fine while the error was displayed on my repositories, but other people reported commits lost or mangled. Maybe there was something more to the Javascript display error?
"Sorry guys, there was a Javascript error displaying an error when there was none. We've deployed a fix for this and everything should be good to go."