When the Detroit Lions acquired cornerback Kevin Barnes last month, they sent a conditional draft pick to the Washington Redskins. The conditions attached to that pick were never made public, but at the time there was no sense that they wouldn't be met and the pick wouldn't ultimately belong to the Redskins.
Things changed on Tuesday when the Lions decided to waive Barnes. It still wasn't initially clear if the conditions on the pick in the trade were met, but Tim Twentyman later reported that they were not. This means that the Lions will not be sending a pick to the Redskins after all.
League source tells me that the Lions don't lose that conditional late-round draft pick by releasing Kevin Barnes.— Tim Twentyman (@ttwentyman) September 18, 2012
Essentially, in terms of compensation, the trade never happened. Barnes is now a free agent and the Lions won't lose a pick, which is probably why they didn't hesitate to release Barnes when they were able to claim cornerback Jerome Murphy off waivers.