It's certainly possible that they stole the bitcoins and paid for a few days (a week?) worth of goods.

But 1) the article does not provide any real evidence to support for this theory, 2) it's not a sufficient amount to be a viable strategy, and 3) the evidence even linking the thefts to NK sounds somewhere between non-existent and very flimsy.

When the FireEye report's leading point states: "...there are no clear indications of North Korean involvement", it's not good support for such a broad statement as the title of the article.

Again, it's definitely possible, but too little information appears to be available to draw this conclusion.