Pay Offline / Digital Downloads

I force Paypal payment 99% of the time.  However, I allow walk-ups on picture day to pay via cash using the "pay offline" option.  I was doing a test today (as a test customer), and it seems that if I have a pre-order gallery and allow "pay offline", then I was still able to select photos and fill the spots in the pre-order even though there was never a payment applied on the backend.  In other words, it seems like someone could just select "pay offline" and download images for free.  I was expecting to have to manually go in an confirm/apply a payment to the order before they'd be able to do that.  Is there an option or something I'm missing?

thanks!

That is just how it is going to work. But are they really downloading photos right after a pre-order? Instead of pre-order just have them buy the photos since they are already ready?

No, it's typically a few days to turn around the photos from that session to make it online.  However, the same customers will often have action shots or other team/individual shots in other galleries on the site.  So in theory they could just submit an order with the "pay offline" option, then fill that order with shots from other prior galleries.