The authors, ( Chris Shugart and TC ) would have to answer this personally, but here's my take on it.
I'd interpret this as start with lbs x 15. Then drop 500 calories from your initial calculation of lbs x 15, and stick with that. Unless you're not losing about 1 lb per week. Unless you were massively overweight to start with, dropping another 500 calories would be way too much.
I would deduce from the article that you'd just adjust the calories after that, according to your results.
I started the T-Dawg diet after New Year's and IMO it kicks ass. I'm not after a huge weight loss, and just wanted to start seeing some results. I grabbed the basics from the food choices, and eat from those choices every day. I still cheat at DQ on Sundays, ( a medium choclately Blizzard every Sunday, whether I need it or not ), and I may be losing weight so fast that I have to ramp up the calories, and / or carbs.