Angel Food Cake - Sugar-Free but not Sucralose Free? What?

The label on the top vs the label on the bottom.

The task for the day was to go to major grocery stores in a 50 mile square area. I was to buy either a sugar-free cake, gluten-free cake, or dairy-free cake. I settled on a major grocery chain which I will not divulge. I went to the bakery section and I had trouble finding any sugar free cake. A clerk said to check out the frozen end cap. After walking about 100 feet from the fresh bakery section, I had found the frozen refrigerated end cap with the sugar-free and gluten-free cakes. 

Surely there should be a sugar-free cake in this store. I had seen a gluten-free cake and upon further inspection, I located a sugar free angel food cake. The angel food cake was cleanly packaged and it was within its expiration date. I had purchased the cake and I was going to check it out further when I got home.

After I got home and upon further inspection I saw the ingredient sucralose as the last ingredient on the label.  I test to make sure I do not have a high sugar readings or spikes. I had no idea that a sugar-free cake would include this in the ingredients. I went to bed wondering more about sucralose.

The weather was fabulous outside and I was outside working on the yard. My neighbor Dave White was walking his dog down the street. He was a diabetic. I mentioned my experience with the Sugar Free Cake. Upon hearing the sweetener was a preservative name sucralose, he exclaimed Sugar! 

I than spoke to the owner of Ventito Bakery about the Sugar-Free cake with the Sucralose sweetener. She was angry. When she called back, She said "it was so sad how a sugar free baked product which should be low carbohydrate, low sugar, fat free dessert which many  think would not be the case. Turns out the cake could be destroyed and could ruin it by adding a sucrose preservative which is adding sugar to alcohol. This is why obesity and diabetic is so bad in this country. She sent me the Wikipedia definition of Sucralose.

"Sucralose is an artificial sweetener and sugar substitute. The majority of injested sucralose is not broken down by the body, so it is noncaloric. In the European union it is known under the Enumber E955. It is produced under the chloriantion of Sucrose."

So I ask what really is the difference between a sugar cake which is sweetened with the preservative sucralose and a cake that is not sugar free?