It’s not a guess, going by the official communication posted it can’t have been Kris. Kris was just a likely candidate, which resulted in this change on Christmas Eve:
However, bans still continued to happen for the next two days, until this information got posted:
The devs aren’t lying about anything, they are definitely dodging the question what actually got fixed though. It wasn’t anything client side, there hasn’t been any further update to the client files. Which, of course, makes a lot of community members very curious what actually caused them to get banned, and how to possibly avoid that when the ban bot goes crazy the next time.
There also hasn’t been any word yet when the spell will be reverted to grant two treasure maps again.