I watched the 1st episode of “Taboo” TV show and here is a piece of the description of the main character given by his enemies:
I would guess that confidence allowed his true savage nature and
mother’s madness to emerge. The necks he broke always belonged to
officers. And then there is the setting ablaze of a Navy boat in an
experiment with oil and mashed potatoes while drunk. And a fight with
a bear in Chancery Lane, a rebellion against the cooks for bad
custard, started by him, and he raved about fortunes and hidden
treasures. He tried to recruit other boys to go down the river to
India, to trade with Red Indians, to take gold from the Aztecs. And
more necks, more whores and more custard. And finally…
I suspect that the main character actually didn’t break officers’s necks because it’s the crime that a soldier couldn’t have committed without consequences. I guess that there is some figurative meaning of “the necks he broke”. Am I right?
I’ve never heard breaking necks used in this context but I suspect the soldier in question was a pain in the neck.