Thinko

I just saw a new word get invented.

We are in the public economics workshop going over a rough draft of a paper. The Czech professor was pointing out a mistake, and said, 

"You repeated it twice, so it is not a typo, it is a thinko."

We all liked this new word. It makes sense. A typo is an error in typing, and a thinko is an error in thinking.

Edit: It seems that the word is already used in computer science, and it means the exact same thing.