MISTER McCHESS The word "mistake" can have dozens of different meanings. Even as regards to chess the word "mistake" can have several different meanings. You yourself used that word and gave it two different meanings in your posts.
Just because you say that move was a mistake does not mean it was a mistake, A GM might make that move for a very good reason.
But ,most of all we have defined "mistake" in a certain way for clarity. So it relates to our long discussions in this forum.
Defining terms is very important in a discussion so there is a mutual understanding of important concepts.
Otherwise we could have a big waste of time as many people could delay conversations as each could have a different definition of important words.
White can’t be winning; he has no king!
That means he can't be checkmated.