Well there ARE still calories (energy for your body to either use or store) in protein and fat. They're just harder for the body to get at. But if you eat more energy than you need, it will still be a problem for weight loss, wherever that energy is coming from. The point of that article is that it is more complex than just "calories in, calories out" or "a calorie is a calorie no matter where it comes from." The body does not treat all food energy equally.
In other words most people can get away with eating a lot more calories from fat and protein than they can from carbs. And yet, because low-calorie diets tend to push you to avoid fats and proteins that, on paper, appear to promote weight gain, they drive you towards carbs. When in fact you will gain more weight from the equivalent amount of calories in carbs than you would from the same amount in protein or fat, because of how your body accesses that energy.
That doesn't mean that you can eat unlimited fats and proteins and never gain weight. It is always possible to eat more than your body needs, and that leads to weight gain. And people who are stuck at a weight loss plateau or who have only a little bit left to lose may find that they need to fine-tune not only their carb intake but their fat intake as well.
Plateaus in weight loss, like what you are encountering Bill, is a common phenomenon. The body likes to be at a certain weight and after a certain point of weight loss, will pull out all the stops (including the brain using everything in its arsenal to convince you to eat more - cravings, hunger, the works) to try and keep you from going any further. Most people find they have to do a bit of tweaking: increase or change up the exercise, fine tune the diet a bit. Anything to sort of shake things up and keep the body off balance so it can't dig in and get comfortable where you are.
