I didn't think the story was true, but my mechanic told me about some guy he knew fishing around under a dash shorting wires with his wedding ring. It turned red hot and he jerked back and peeled all the skin off his finger. You were lucky.
A 5 second dead short on the terminals with a wrench could have caused some damage - there would have been hundreds of amps flowing through the plates. Probably the easiest way to tell is if the electrolyte in any of the cells has gone cloudy or if the fully-charged rest voltage is below 12.8. Just be sure to remove your jewelry and wear eye protection when you check.
2015 Rockwood Signature UltraLite 8282WS Platinum, GY Marathon LRD, TST 507RV TPMS
2005 GMC 2500HD CCSB D/A, Curt E16, Prodigy P2, Garmin RV760LMT w/BC-20 b/u cam