If they let him walk for nothing, they absolutely blew it, and fucked it up multiple times. They blew it by not trading him when Getz took over, they blew it by not putting cash in this winter for the Reds deal, and they blew it by getting literally nothing for the right to pay Luis more money to go away.
At that point It's like having a junk car on your lawn that the city is about to fine you for when the local scraper rolls up and offers to $50 for it, but you refuse because it is worth $60, and instead pay the fine.