You were not a great caretaker for the baby bird. You sat on it, put a rock on it, and even pushed it outside. Ultimately, however, you did right by the baby bird. You did what few bears would have done. Then again, most bears probably would not have had a problem fighting off, or at least scaring off, a coyote. That is not a comment on your lack of fighting skills. Well, it is, but what matters is that your heart was in the right place. That heart is no longer beating because you make terrible decisions, but at least when it was beating it kept beating for the right reasons.
You tried. You succeeded in a way, but you just do not get to celebrate that victory.