Then it's only a matter of time before consumers start gaming the system right back. Write a poor review, await a refund offer, then write the real review.
Yep, can't let the word spread that someone peed in the co-mingling pool. That might cause a panic!
Also: can't let the word spread that "prime" shipments get silently substituted for 30-day slow-steamed-in-a-containers-and-then-USPS shipments. That wouldn't reflect fairly on the product!