Your "bug" is in your code; the pragma is not the problem; it's the way you are failing to use it.

When you use -T you are telling your script that some of your input (in this case, the file you're spellchecking, foo.pm) or other external datum is not necessarily trustworthy; read "input" VERY broadly.

So you must untaint (generally, done with a regex that passes only chars you determine to be "safe" for your purposes. perldoc -q taint offers one minimal pointer, but you should consider reading Tutorials and/or Ovid's CGI course, which planetscape is restoring/has restored to this site.)