Kinda my point - torpedo's a weapon mean to split the hull integrity of rigid steel ships (along the keel with the pressure of displaced water from the explosion). But the way it's drawn, it looks like it explodes right up against an organic being which can survive the pressure of very deep sea, probably deeper than any nuclear sub (talking the ballistic missile submarines). I'd have expected it to be stunned and require some other munitions like depth charges to be finished off.
On the other hand, maybe its "hull integrity" was compromised because it is designed to survive the pressure of the depths - it was struck pretty close to the surface, so the overpressure in just one spot at that depth might have caused it to rupture.