How can this kebab have so much protein and so little fat?
Nobody is lying, different Doner meats have different fat contents, that's true of the ones in the stores as well as the ones in restaurants. Doner is a processed meat product made of ground meat and fat mixed with spices and usually preservatives. Sometimes fillers and binders are added as well. There's no rule saying a doner must have a specific amount of fat, it's all up to the manufacturer and the product they are trying to produce. 

A "lite" doner may sound like a contradiction in terms but someone more health conscious may pick it because it has less fat and calories.