Magic (siḥr) appears in classical lists of major sins, but scholars did not uniformly assign every activity described by this word one identical theological judgment. Some forms may involve explicit unbelief or corrupt worship; others concern deception, harm, or different prohibited practices.
A severe prohibition and a judgment that a particular person has left Islam are not the same proposition. The facts of the particular act, its content, and relevant beliefs must be established before one can even analyze the applicable category; a generic label is insufficient.