Again, imo, I believe he was'nt a true Nazi and did'nt desire to continue the fight with the british, a people whom he greatly respected.
Lots of professional military men who weren't Nazi believers fought, not for National Socializm, but for their country.
I haven't studied these events in such detail as you, but what I have read tends to be the account Woodlouse stated. Hindsight is 20/20, but at the time, I belive Langsdorf was led to believe a British task force was en route to deal with the Graf Spee.
TURKEY TROTS TO WATER GG WHERE IS RPT WHERE IS TASK FORCE 34 RR THE WORLD WONDERS