Mueller covertly encouraging impeachment while misleading the public. If he and his team thought Trump should be impeached, they should have made clear all the laws that were broken and then stated they could not indict, but they didn't. Mueller is a crook.
Yep, he just blatantly lied about that.
We all know POTUS can't be indicted, but that doesn't mean that Mueller could not report legal violations that would be indictable if not POTUS and then use those for impeachment, then indictment.
Mueller just lied his ass off to start impeachment for political reasons, not legal.