This isn't a bug so I'm not sure that contrib applies to this. You can use the delete button in Customers > Orders in the regular osc admin panel to delete the "Pending" orders. I'm concerned that these "orders" show in the customer's "View the orders I have made" screen, and then can't do anything with it. I can delete them, but they can't, or even pay for them.
Does this RCS contrib do anything with that by letting them view an incomplete order, and then finish up and pay for it? From a technical standpoint, what exactly does this contrib do? It looks like RCS assumes the items are still in the cart, which, in my experience, isn't always the case.
Like I said, once I turn this over to my customer (who I'm doing the cart for), if I have to tell him he has to log in and clear out incomplete/unfinished orders all the time, he'll look at me funny.
Give it a try. Add items, check out and get to the "Confirm order" button. Then clear your cart and go to My Account > View the orders I have made. You'll see the uncompleted order in a pending status, but can't do anything to it.