@lael, as for the new Shield shiled there is a thread here
and I guess @mohit would be the person to ask about your particular issue, if this will be fixed on the new one.
As for the A5 5V-tolerance, I’m pretty sure it’s not, but you could have been lucky or you only frazzled the ADC part of it 
, which would not show on a digitalRead() test.
But if it is in perfect condition now, you should not need to worry about after effects of this - just don’t do it again 