Captain Kennedy of Rawalpindi must have had very poor eyes, had not done well in math, or RN naval recognition silhouettes were poor. He identified KM Scharnhorst as Deutschland, despite the fact that Scharnhorst had two forward triple gun 11” turrets and Deutschland only one. Plus, it was known that Deutschland was operating alone and it was clear that Rawalpindi’s attacker had a companion. Closer observation would have revealed it to be a sister ship, likewise mounting two forward triple 11” turrets.
In all fairness to the Brits, I believe this was the first sortie of Germany’s only heavy battle squadron, as Scharnhorst and Gneisenau had only just finished working up. I don’t think the RN was expecting to see them out in the north Atlantic.
I doubt the part about German sailors jeering at the survivors of Rawalpindi; the Gneisenau took aboard several survivors. And the Kriegsmarine through the war was generally known for humane treatment of British crews. Even if there had been some jeering, it isn’t the same as machine-gunning.
It was their first and it was a quickie, lasting only from 21 through 27 November.