[ajross]

It's more that they display both. Unlike git core, github actually tracks "push" events to branches (git doesn't care, it only sees commits) as distinct from the commits they contain.

So presumably it would have shown the rails developer pushing a change authored by Homakov.

[technoweenie]

Git has no real way to track that, only commits. We do track it internally, but AFAIK it's not exposed except through post-receive hooks.

[Tobu]

ref changes are tracked in the reflog, but the "pusher" (as opposed to author and committer) isn't.