Decided to pull this out of the hits on PoW thread as it is a separate topic.
Here's my take on the concern as to whether the turn took place before or after Hood was hit on her boat deck:
I believe that Holland knew exactly what he was about. He was closing in to a point at which he felt comfortable that his two ships guns could have optimum ability to hit and do damage to the enemy, while maintaining what he perceived to be the optimum distance for his two ships' defensive capabilities.
The two 20 degree turns were likely planned whether the enemy was retaliating or not. Holland wanted to get the full weight of his ships fire as the range decreased, while trying to stay forward of the enemy's beam to prevent them crossing his T, So the signal flags for the first turn were hoisted at 0555, but the execution order only came after the Germans had opened fire and the ship was hit.
Ted Briggs' description - in which a turn is ordered as carnage reigned aboard Hood - and he mused that "not everyone on the flag deck is dead then", with Hood turning, firing a salvo, then the fatal blow comes....is very likely what he experienced in the hoisting of the flag for the second turn just before Hood blew up. In the trauma that followed, and with the well established idiosyncrasies of eyewitness recall, things got merged in memory.
So, to summarize, just before 0555, the first turn is ordered and the flag is raised, The Germans open fire. Hood is hit by PG at about 0556+, the boat deck fire erupts. Holland orders "Execute" and the ships go into the turn, opening the A-arcs at about 0557:30 or so (as shown on PoW's salvo plot) before the turn is complete.
Then the spotting top his hit, the base of the bridge is hit and in the increasing carnage Holland orders the second turn, the flag is raised as described by Briggs, and PoW sees it.....then the fatal salvo falls...
My two cents...
Qui invidet minor est - He who envies is the lesser man