I'm betting your porc is still in your tank, alive and well. I can't believe how many times I've been CONVINCED that my porcupine puffer was gone when actually he's just hiding/sleeping in a nook, cranny, crevice, etc. They are so good at camouflaging themselves that I have stared with flashlights from all angles of the tank and not been able to find him, only to have him show up again the next day when I dropped in some feeder fish.
To this day it STILL amazes me how well he hides during the day - I've mourned him several times and he's always alive and well when he feels like meandering out again.
Sue