I never read "visibly blown cap" part , only cap 1/8 inch out of the board ...

Direct current can zap you nicely and blown cap can be tested (it will say BAD) but some of them CAN hold a charge (LESS charge though).

There are caps that don't even look bad but are actually empty and not working ,  to be completely sure you need something that can measure capacity (ability to hold electrons) and to do that you first need to remove cap from the electric circuit otherwise
god will know what are you measuring.