IMO your playing word games and takieng an overly nuanced position on what is essentially good advice.
That you have to practice it at least somewhat correctly is a given--or should be.
But even then--to an extent--the reps MAKE skill, think of it like this, the first time you pick up a basket ball most folks don't know how to shoot a free-throw---but if you keep trying you'll eventually get better ie more accurate with the shot.
Good coaching will vastly speed the process up.
Another thing to consider is that even with good coaching, logcially you won;t be practiing new skills with much skill--at first, so in effect you'll be practicing a FLAWED skill, until it gets better.....thu practice.
As far as how one knows they are getting quailty training--good question--and a tough one as well.
If you have no expereince ot the arts then "knowing" what is quality and what is not is going to be tough to figure out.
Just because your teacher has won a lot of tounaments--for example does not mean that he/she can teach you to do the same.