When a global validator failed, a exception is thrown and never catched.

The label of error is lost and we are unable to display an understandable message to the user.

For example, use UGC plugin (with form.xsl helper) to submit a news with start and end date. If you choose a end date < to the start date, a global validator failed but the user has only an error "An error occurs whiling submitting the content" in an alert box.

It is not possible to display the label of original error at top of the form for example.