apushatayid,
You are correct, but I thought the discussion had digressed somewhat since checking lettuce was mentioned. Bagged lettuce could be washed or greenhouse grown, and there is a difference between romaine and iceberg. The checking afterward is just random sampling to ensure that the process was successful at preventing/removing bugs. I assumed that the comparison between checking at home and by a mashgiach was referring to a food service establishment.
My point remains the same; although in some areas, hashgochos are more machmir than individuals, in many areas (more, I believe), they employ kulos which many people would prefer not to.