ST v Maidstone & Tunbridge Wells NHS Trust  EWHC 51 (QB) provides a first instance consideration of material contribution causation in the context of an alleged delay in transfusion.
The evidence was held not to be sufficient to satisfy the causation burden of proof. There was no objective evidence that the various conditions may have combined cumulatively or synergistically to cause the child’s strokes.
The trial judge commented on the expert evidence at :
‘…However whilst I do of course understand the importance of clinical experience, any decision I make must be founded on objective evidence (including authoritative medical literature, laboratory findings and clinical observations), rather than merely on personal opinions.’