I’m not sure if this is something you guys can or want to help with. The bathroom at my current job is completely free of graffiti except for the words “itik nuliak” written very clearly in Sharpie. It’s not a language local to where I live and putting it in Google translate doesn’t do anything. It’s been bothering me.
I think it’s hilarious that you have gotten it translated and now have a suspect.
I suggest you name and shame them in your correction, even if only by an identifier only you and they would understand.
It’s enough for me to let them think that someone in the office speaks an obscure language they are interested in. The person in question has been talking about the Inuit a fair bit recently. That’s how I know who it is. I can’t imagine there are many people who have ambitions to learn Inuit who don’t already live in Nunavut or Greenland.