Young Ed, Sorry you don't get it. If you have the bottom of your filter going to the oil gally YES THE OIL AND DIRT WILL DRAIN FROM THE FILTER back into the oil gally but you will have oil presure on start up because the oil gally is the presure side. Never thought about it b4 but when you think about it your not getting the presure to your bearings you should be becauce it has to refill the filter. If it is hooked up right the filter will still be full because the relief valve will not open to let it drain unless under pressure. Look at the pic and see where the oil flows. Your filter has more surface on the outside to catch dirt and it can't return to the engine from the top. If you don't believe the flow chart you aren't going to believe me so do it your way.
Bill