Sure, I get it, but when it happens you're just in a bad world and you can either try to put breakpoints in every copy of the file that Firebug/Devtools detects

Sure, I get it, but when it happens you're just in a bad world and you can either try to put breakpoints in every copy of the file that Firebug/Devtools detects, or you can say *&$% it, and add "debugger;" in the file.