Aren’t channel misalignments a product of the Technicolor IB print, not the photography, though? So fixing that shouldn’t be at all controversial. Though I must say I’m not offended by fixing flickering etc. that may have been a product of the original photography.
I believe he mentioned the models were misaligned differently than the background plate, so in that case ut would be on the negative.
In that case some of it would be on the negative, but it’s impossible to tell which channel misalignment happened during compositing abd which happened as a result of the tech ib process, which is why he corrected all of it, just to be safe.