When ResourceLoader combines multiple .js scripts into a single bundle, they're given separate function contexts (thus separate local variable namespaces) and are executed separately with try/catch wrappers to isolate faults.
This can let a broken gadget for instance break important parts of the UI if they end up getting bundled together:
unmatched ) in regular expression <- syntax err in a gadget addButton is not defined <- editing widgets haven't been loaded either
A syntax validity check might be a good thing to throw in before (or after?) minification.