It appears that the blank gets stripped out of the regex when javascript compression is enabled.
Disabling compression in the FacileForms configuration works around the problem until a better fix is found.
Edit:
change the line
var ex = /^(\+[1-9][0-9]* *(\([0-9]*\) *|-[0-9]*-))?[0]?[1-9][0-9\- ]*$/;
to
var ex = new RegExp("^(\+[1-9][0-9]* *(\([0-9]*\) *|-[0-9]*-))?[0]?[1-9][0-9\- ]*$");