That's not correct, you can get back to any ref in the reflog, including those that you moved away from with git-reset --hard. Those commits are just dangling but are easy to get back to. I've got a presentation [1] that goes into how to use the reflog and how the various flags in reset work (among other things) that could explain more.
[1]: http://tednaleid.github.io/showoff-git-core-concepts/