Don't all singers change the songs they sing? If only by tone, intonation, key, but to a greater or lesser extent to suit their style, their capabilities? I'm not familiar with the particular example quoted, but don't see it as a heinous crime. The original still exists.

John Connelly has changed the chorus of Punch and Judy Man, but I've yet to find anyone else singing the new version. Are those who haven't changed to be condemned?