Glycerine is not a carb, but it does contain calories. So they do not have to list glycerine in the carbs, protein or fat part of the nutrition label, but they should include it's cals in the total calories. You can often get a rough idea of how much glycerol there is in a bar by subtracting protein, fat and carb calories from total calories. The unaccounted for cals are usually from glycerol.
Although glycerol's impact on insulin is negligible, it can temporarily impede lipolysis via negative feedback (because glycerol is the main metabolite of fatty acid oxidation). Glycerol is also readily converted to glucose or stored as fat, so it would still seem prudent to limit it's intake.