Yes, the Universal board does have reverse polarity protection. What will happen is the diode D1 will get very hot, but it will protect the board. I guess is you leave it hooked up backwards for a long time it will smoke this component, but I have never tested that. I need to update the web site with documentation stating that if you power up your board and do not get a red LED then the battery must be connected backwards.
When you hook the battery up right now will the board power up? If not then D1 is blown, but the board will be fine. Please email me and let me know so I can replace D1 if needed.