Perhaps I'm missing something here - I don't see any back and forth. Just a very rapid upgrade to 2018.10 almost immediately after going to 2018.6.1. It does seem unlikely that a new software update could be pushed and applied that quickly after completing a previous upgrade, but perhaps not impossible if it's a small incremental release (fixing issues with 6.1?).
Look at the first image in their post. It went from 2018.10 to 2016.6.1, and then from 2016.6.1 to 2018.10 an hour and a half later.
I feel like this is just Teslafi misreporting or something.