esd damage is cummulative and unpredictable in complex setups. the card could work fine for days or years or be unstable, or completely unusable
thats why they make esd bags. and techs use ground straps etc. when i worked at IBM we had ground straps, esd boots grounded work tables and tools and ionizer boxes.
if you ever pick up a card off your floor that hasnt been stepped on or even touched and it doesnt work youll know. well conductor oxide or esd damage.