Do these fish track

[rfxcasey]

Playing 1943 German campain with flotilla 2 and was in shallow water near liverpool when I was spotted by a patrol vessel at night. I dove to evade and launched 2 torps both missed. Well the vessel was circling trying to get a bead on me and all of a sudden he exploded and split in half. How is this as the torps clearly missed? It's like they came back boomerang style.