But that's still fudging two fundamentally different things, "bearing" and "location", in a manner nobody would do in reality. If Spock says that the location has not changed, then it automatically follows that the bearing has changed.
Kirk does not need to have any idea of the bearing or the distance, because he has told Sulu to keep track of those.
Is it plausible that NOMAD really remains immobile throughout the battle? That is, from the moment Spock gives the bearing to the moment Sulu fires his torpedo? Certainly, because NOMAD's bolts travel at very high warp and could easily pound Kirk from warp to immobility before Kirk left either the range of NOMAD's weapons, or the range of his own photon torpedoes.
And a separate episode, "Elaan of Troyius" showed us that "all tubes" only as forward facing tubes.
But if torps can't
fire over the shoulder, then "all tubes" would implicitly only mean "all applicable tubes".
Really, the ship has to be stripped of aft phasers as well if we're to believe that the command "All phasers fire!" in "Balance of Terror" did not involve the ship spinning around while firing...