Here is the answer from a local MDC officer
This is from a conversation I had with Tom Davidson Saline county.
He said that releasing a fish or two is not illegal, he said he doesn't like to see it happen when you are using buckets, baskets or stringers because of the stress on the fish and they will likely die, those who use the proper live wells, it isn't an issue.
He did say however, if you go and catch 2 fish and decide you don't want them and release them, you have possessed them and therefore are part of your daily limit, so if you go back out that after noon, and say the limit is 15 fish for example, you will only legally be able to keep 13 more fish. If you keep more than that you are culling and that is illegal.