I've first posted on apache infra to make sure the mirror wasn't an issue on apache's side and they validated that it wasn't.
Followed up with a post on github.com support / discussion list. http://support.github.com/discussions/repos/5948-lucenenet-apache-mirror-is-still-out-of-date In case anyone wants to subscribe to the conversation or add comments, you'll need a github account. - Michael