The term "unemployed" in this context is a legal - as opposed to a factual determination. To be unemployed, you have to actually be looking for work and you must be within 15 weeks of having lost your job I believe. And yes, you need to be collecting some benefit. After that, you fall off the roles.

So...when more people fall off than go on the unemployment roles, regardless of whether jobs are created or not - the unemployment number goes down.