One theory doing the rounds is that in drafting the statement Defra assumed they had a deal with the Treasury - only to be told to find the money from their own budget.
That would explain why Wales and Scotland missed out. Why did the Treasury pull the plug, if it did?
Scottish First Minister Alex Salmond says it might be something to do with the general election.
Politicians west and north of the border say the UK Government should pay up as its laboratories were the source of the outbreak.