Kind of a side issue here, but still within the scope of the original question:
Could there ever be a circumstance in which a laicized or defrocked priest could licitly celebrate Mass?
I am not referring to validity. Even if it were illicit — if he said Mass for no good reason, just out of disobedience to the laicization order — the Mass would still be valid, and the species would become the Body and Blood of Christ.
I have in mind here (and I know this is extremely hypothetical) a situation where, for instance, the Eucharist is urgently needed — someone is on the brink of death, needs Viaticum, there is no other priest or church nearby, and this is the only way to acquire the sacrament — or where a body of the faithful is stranded without access to the sacraments for an extended period of time (not just “it’s Sunday and the faithful need Mass to fulfill their obligation”), unless the laicized priest says Mass for them. This would be extremely rare and unlikely, but in some isolated area, or in a place where there had been some great natural or man-made disaster that cut off access to the outside world for a long period of time, it could conceivably happen. Another example could be a prison camp during wartime where the only validly ordained priest available is a fellow prisoner who just happens to have been laicized or defrocked.
Any thoughts?