It is common for Norwegians to use the word "texas" as and adjective to describe a chaotic atmosphere. They use the word without capitalization and it applies to conditions, not people. But the origin is in the ignorant assumption that Texas is like the "wild west" represented in a some movies.
The thing about stereotypes, though, is that there's a reason for them. Even reading this question, in the back of my mind, I pictured the "typical Texan." This of course isn't to say that ALL people from Texas are crazy, but in general they do have a unique view of the world and a stubbornness that keeps them set in their ways.
Texas and the South have often been the recipient of the "crazy southerner" stereotype. "Going South" was used as an expression meaning to lose it. Most stereotypes do have a basis in truth, but we know not all Southerners are crazy, and certainly not everyone from Texas is either. Texas happens to be a very visible part of the Southern United States.
Anyone can be stereotyped, and it isn't surprising that people from other countries are coming up with terms for people from the USA. Even in the USA we have stereotypes about Texans. It makes one wonder what exactly happened in Norway that made them use the term "Texas" to describe crazy.