Yes, from what I’ve read you’re absolutely right — the methanol does indeed usually come from pectin metabolizing microbes.

This is the paper I used as one of the main sources: Methanol contamination in traditionally fermented alcoholic beverages: the microbial dimension.

There the researchers write “it has been severally reported that microbial fermentation of substrates rich in pectin can result in the formation of methanol [but] recent studies have also shown that the ethanol fermenting yeast, S. cerevisiae, has several strains with slightly different metabolism with some strains possibly producing methanol.”

As to Pectine Milipedes, I’d be very surprised if there are millipedes in moonshine fermentation tanks…