The user was quite prepared to ditch the tool altogether and find another because it didn't Just Work.

That would probably have been a perfectly reasonable thing to do. Depending on various things, it might have been more reasonable than going through the script changing ours to mys. It might even have been easy to find a better replacement written by someone who cares about backward compatibility (or has enough Perl experience to avoid global variables when lexically scoped ones will do.)

Since you did urge your sysadmin to fix the script, however, I hope you also urged him to submit a patch to the author. Not only will you both know that you did your part in helping others in the same situation, but if an unrelated bug fix for that script comes out next month maybe your sysadmin won't have to spend more time fixing the tool before he can use it.

-sauoq
"My two cents aren't worth a dime.";