You're right in that this was only a test. However, as I understand it, they don't have to have 3 "real" people on board. They can use ballast to simulate the other two.
So the rules stipulate!
In any case, they hadn't given 60 day notice of intent when they flew the last flight, and I heard no mention of them carrying ballast for the "other two" crew. IOW, the last flight couldn't have qualified as an "attempt" on the prize.