Looking at the definitive map of 1990 produced by two of the participants.
Look at the Baron's and Schmalenbach's map most recent map 1990, and see for yourself. Lutjens turns away to starboard at 05:55 in compliance with his instructions to avoid entanglement with British ships.
The Bismarck turns only gradually away, exactly as one would do if one wanted to maintain accurate gunnery. She is not on 270T for any length of time, if she made that at all, before swinging back to port. For most of the first turn, since she is not on 270T her rate of change relative to PoW is not zero. In the film there is no suggestion she is at 50 degrees course difference to PG, perhaps no more than 20 degrees divergence.
I ask again, will someone with a clear copy of the PoW salvo plot give the "assumed course" value at the top? McMullen's reductions in range on successive salvoes are composed of two elements: down ladder range reductions due to initial over estimation of range but also the the faulty rate from the clock due to poor inclination estimate, hence "enemy course".
Of course Bill's calculations are valid for Bismarck's firing too when she and her target are manoeuvring violently and if Bismarck cannot hit with 8 guns between 06:03 and 06:09 (not proven) then Aylwin's chances with single gun salvoes are even lower.
All the best
wadinga