If you actually dig into the de facto structure of the government, rather than the de jure, I bet you'd find that the conservatives never actually
controlled the purse strings. Remember, there's more to controlling the purse strings that first-order apparent raw voting power. What would it have cost the conservatives to shut off the money flow? If the liberals made it more than the benefits, then regardless of the de jure structure of governmental power, the conservatives never had de facto power to cut the funding off.
He who pays the piper calls the tune. If you think you've found a place where there's an exception, you haven't correctly identified the payer.