My favorite book on the subject is
Shackleton's Legendary Antarctic Expedition.
Author. Caroline Alexander.
Contains some amazing photos by Frank Hurley.
Mind you always thought it was a mistake not to award the Chippy his Polar medal. I get it that the Chippie was a miserable bastard but Shackleton did kill his cat. Without the Chippies skills they would never have made it home.
It was in my old School - the 3 "houses" were Scott, Shacklton and Amundsen and there were maps etc on the wall outside the Head Masters study. Often wonder what happened to them as the year I left in 70 they turned it into a Middle School from a Secondary Modern - then last year they closed the place and invited all old boys/girls around and they weren't there anymore.
I would have to re-read the book. But I think your right. He was not happy with the way Shackleton was directing the exped. I think after they killed his cat to conserve food he went a little off the rails.
From the book 'Endurance'
McNish died in 1930 and for a pauper received and uncommon funeral. His pallbearers were drawn from the RN and the NZ Army provided a gun carriage to carry his coffin. He was buried in an unmarked grave in Karori cemetery, over which in 1957 the New Zealand Antarctic society erected a headstone.
No mention about that in Shackleton's book if i remember correctly. It was shown in the Branagh two part film though (available on 4OD if anyone's interested. Worth a watch).
Shackleton deserves more recognition i feel. Mention the Antarctic, and people think of Scott. Ok, he reached the pole, but he wouldn't have hadn't it been for Shackleton. Also, Scotts expedition was primarily for scientific purposes with the pole a secondary objective. Shackletons tale of survival against the odds after the Endurance went down is one of the greatest stories ever. How he never lost one man still baffles me.