I'm more confused by the fact that the OP freely submits a PR into an open source repo but then wants to use "copyright" because the code he submitted ended up being used under the wrong name, which was then corrected.
It would indeed be copyright violation to improperly attribute code changes. In this case I would absolutely say a force push is warranted, especially since most projects are leaning (potentially improperly) on Git metadata in order to fulfill legal obligations. (This project is MIT-licensed, but this is particularly true of Apache-licensed projects, which have some obligations that are surprising to people today.) A force push is not the end of the world. You can still generally disallow it, but an egregious copyright mistake in recent history is a pretty good justification. That or, literally, revert and re-add the commit with correct attribution. If you really feel this is asking too much, can you please explain why you think it's such a big problem? If it's such a pain, a good rule of thumb would be to not fuck this up regularly enough that it is a major concern when you have to break the glass.
Mistakes happen, I guess this hurts his 'commits in a public repo' cv score.
What is your understanding of what license and rights the author was providing them - understanding this I can figure out where you are confused.