Received a reply from Groovy Foods saying that it was mandatory to include fibre in total carbs! I replied saying not in the UK and proved it with a photo of some prunes where the sugar plus fibre exceeds the total carbs figure.
I also wrote to Morrisons who said they've spoken to Diabetes UK:
"They confirmed that, when calculating carbohydrates, ingredients used for baking or cooking from scratch are added into the overall carbohydrate count for the meal. Then, if the recipe is for more than one person, it is divided as per portion size to calculate the intake. In a situation where an ingredient has fibre included in the carbohydrate count the effect on the calculation is reduced by the other carbohydrate containing ingredients, thus making any issues with matching insulin levels less likely. This is as opposed to a ready-meal , for example, where the carbohydrate figure reflects directly what is about to be consumed in that meal."
I have replied explaining that as coconut flour is a favoured ingredient for those reducing their carbs, it's less likely to be mixed with other carbs but since Diabetes UK have confirmed what they wanted to believe I think I am fighting a losing battle!