Man your logic doesn't fit with this scenario at all. The guy threw back the smaller fish and kept the largest one he caught. And where do you get the idea that a 5lb bass is too old to breed? That fish, was probably no more than 7 years old, LM in KY have a much longer life span than just 7 years and that fish had many more egg laying years ahead of her, have you not seen LM on the nest before? most of the ones I see on the beds in the spring are well over 5lbs!! The KY State record was almost 14lbs and was probably close to 20 years old. I don't disagree that selective harvest can be a good thing, but this is just silly. Besides, after looking at that fish, it would be lucky to hit 4lbs.
http://www.fish.state.pa.us/pafish/b.../pics/fig1.gif