Saw Crumpton throw up soon as he came off so possibly he was unwell rather than a tactical change.
That's not good..I hope he was properly checked over.
I recently read about the young French player who was vomiting post match. His symptoms were ignored by those around him. Sadly he was found dead next morning after suffering a brain bleed. He had incurred a head injury during the game and the HIA protocols were not followed. No correlation was made between the knock on the head and his vomiting. The latter being a symptom of cerebral haemorrhage.