Does this seem right?

This question isn't about me, but about my husband...
In November, we both had our annual check-ups, and our doctor told me some horrible things, but then told my husband that he was pre-diabetic and set up with this special "Wellness Weight Loss Program" that he runs out his office. He's in his early 40's, fair physical condition, only had 20 pounds to lose. It was his blood sugar that was the real issue.

The dietary specialist (I don't know her title and qualifications) put him on a 35% Protein/35% Carb/30 Fats diet, and with two protein shakes and two protein bars a day to 'keep his blood sugar balanced'. I learned to cook low-carb, cut pasta, bread, chips, cookies, etc out of our diet entirely, added lots of high fiber like beans, oats, etc.

Even with those protein shake things, he is hungry. All the time. He's exhausted, cranky, headachy and can't concentrate at work. He's lost weight and looks fantastic physique-wise, but according to his notes from the dietary specialist, he's not losing weight fast enough. She said he should be losing 2 pounds a week, period, and she wants to see that result on the scale every time he comes in, even if he's worked out weight-lifting the night before? She actually told him, "Don't use water weight from working out as an excuse. It's not relevant." when he weighed in at only having lost half a pound.
He finally stopped seeing her after Christmas and stopped trying to use her miserable weight-loss application and switched to MFP with me after she told him that she didn't really understand how the body composition analyzer worked, but "sometimes it gives inaccurate readings" after it showed his body fat had gone up after 1 month of steady weight loss. Our doctor said as long as he checked in once a month with him, he didn't have to see the diet management person. Okay, so far so good.

But last night, when he was once again frustrated because he was genuinely hungry (hot decaf tea and a short walk to make sure it was real hunger) but had completely run out of calories for the day, I started asking questions and doing some calculations.

That's when I found out that he's only eating 1800 calories a day. That's what she wanted to see- less than 1800 calories consumed per day, and was sending him email alerts every day that he was logging over that. (That was on the special application that she used.)
According to the various calculators that I use regularly, his BMR is between 1900-2200 and his TDEE is 2600-2800! 1800? For a 40- something male with only 20 pounds to lose? Is it just me or is that total lunacy?

I've always had a problem with 'shake' diets. I think they don't teach you how to eat real food, nor do they teach you portion control, but I felt that as long as we were using MFP, and he could understand what he was eating and what amounts were appropriate, I could help him make the transition off the stupid shakes when he reached his target weight loss. But now I'm not too sure.

Am I being out of line being concerned with this? Are there people here who this has worked for and come out healthier for it? Or is that diet-manager lady really the reincarnation of Linda Hazzard?