Kelly....

I didn't say that he was eating too much fat, only that if you are consuming a high level of dietary fat, it can register on the ketostix too and produce a dark purple color. The ketostix are only a tool and even Dr. Atkins admits that they are not always an accurate way of telling whether or not you are in ketosis, but goes on to say that most people keeping their carb levels at 20 grams of carb a day would be in ketosis after a few days.
Personally, I don't even use the ketostix. As long as my blood sugars are controlled and I'm losing weight, I know I'm on the right track.
Can you eat too much fat? Sure...you can eat too much of pretty much anything, but fat has a self-limiting feature to it in that you can only eat so much of it before you start to feel a bit uncomfortable or even a bit nauseated. If you're unsure of how much you are eating and how the percentages break out, have you ever tried www.fitday.com? You have to register to use it, but it's free and many low carbers find it's a great tool to help them keep track of how they're doing.
For most people, the percentages break down something like this on induction: 65-70% of calories from fat (remember that 1 gram of fat has more than twice the calories of a gram of carb or protein), 25-30% of calories from protein and 3-5% of calories from carb.