A reset is intended to set all clocked circuits in a known state.

But some circuits can also suffer latchup issues, in which case you can play any number of times with the reset without solving the issue. And it doesn't even need to be on a port pin - with enough abuse, where you just can't keep gnd and vcc locked down, even inside logic in the processor or external chips can suffer. In some situations, you put a charge where a charge shouldn't be, potentially requiring a power loss for hours because you got something similar to a memory cell. In other situations, you just create yourself a thyristor - it's enough with a short power removal to unlatch the signal.