Minsc has apparently been petrified all this time and just recently brought back to his old self.
It was probably one of those damn basilisks! Boo probably warned him to steel himself, but Minsc was overly confident about butt kicking for goodness and got himself petrified like Branwen.
One of my favorite easter eggs I encountered in the past couple years was finding the painting of Guybrush Threepwood from Monkey Island in Uncharted 4. That was a lovely nod.
