Andrew responded before, but I'll expand on the answer.
A deputy head is, through legislation, the accounting officer of an organization and ultimately accountable for all of the decisions made. This is delegated down through the organization. Everyone who has delegated authority has training about what it means. I think everyone needs to recognize that committing the government to a contract and signing off on the use of public funds come with accountability.
This has to be the culture throughout every organization—making sure there is a prudent use of public funds.