That is probably correct when talking about individual heads of lettuce. Except for the inspection process, in which a sampling occurs regarding individual heads that determine if the product meets the USDA minimum requirement standards. But, the receiver or distribution center most likely has higher standards to meet the requirements of the end user, such as your restaurant. If you received lettuce that just met the minimum requirements of USDA standards, you would, in all probability be extremely displeased. Why? Because your restaurant would have too much waste to be tolerated.
This was a top of the line restaurant and the produce was usually perfect.