I find it difficult to tell how I feel about this. On the one hand it seems in this case the health board is trying to ensure the child survives the operation while trying to honour their wish to avoid the transfusion unless it's clearly necessary, which all sounds good. I also recognise that the reason the child is refusing it is due to religion which they probably had no choice but to be indoctrinated in from birth.
On the other hand, all parties recognise that the child is capable of making their own decision and understand the consequences, but yet still gets ignored. This seems like a slippery slope. Where is the line when the court can decide what happens to someone's body against their will? I could understand it if they also claim the person is unable to make the choice for themselves (e.g. too young to understand the consequences, or under the influence of propaganda), but they are not claiming that.