Seems implausible to me. Rather than a self-destruct, it would be more plausible to just disable the explosive trigger altogether. If a torpedo fails to hit target for whatever reason (including, but not limited to the original problem) you don't necessarily want it to explode in some random place. Nor is it clear how, if this failure did occur with loss of all hands, we would ever have known about it.
Despite this, I take the point of the story to be that self-corrective failure detection mechanisms should not be capable of causing greater harm than the maximum plausible damage of the problem they were intended to correct.
Possibly because you don't want your adversary to get one of your unexploded torpedos and copy / reverse-engineer / exploit a design flaw. Tactically that'd be far more devastating than losing a ship or two.
Despite this, I take the point of the story to be that self-corrective failure detection mechanisms should not be capable of causing greater harm than the maximum plausible damage of the problem they were intended to correct.