Last thing before filter should be rinse. That gets any sand in the pipes into the right side of the filter.
Ideally, when you backwash, the sand bed gets all churned up so the lighter debris floats to the top and out. So it ends up in the "out" pipe as far as the backwash valve. When you rinse, things get sent the right direction and any stray bits of sand should end up on top of the sand pile.
From Deep Cleaning a Sand Filter
RINSE - ....rinsing. Rinse is exactly the same as filter, except the filtered water is sent out the waste line instead of back into the pool. This step should always happen after backwashing for two reasons. First, any dirt and debris in the filter that did not get ejected during the backwash is now in suspension with the sand. Immediate filtering could put some of it in the pool. Second, the rinse helps resettle the sand bed for when the system is placed back in filter mode.