It's a good point NWG... I should have mentioned that the friend is an old friend and top notch borrower just like you.
He wanted to bring me new ones or hand me a wad of cash, but I told him no need. Flat slings are not that spendy and are a consumable item. My desire to save them had more to do with that these were still kind of new and pretty, not the typical condition that I toss a sling in the trash.
I bet WaGuns could fill a long thread with stories of the bad borrowers... A previous coworker borrowed our towdolly.
He brought it back on a flatbed with all the studs broken flush on one wheel. "I don't know what happened! Just driving along on flat smooth ground and the next thing I know the tire and wheel were gone!"