Back on the 6th I was told that the change was going to the live site that day. Somehow the actual change to prevent second chance offer items from showing up in the showcase pages was overlooked.
We've fixed this (again, sigh) today. Going forward no new second chance offers should show up.
Sorry about this. It definitely makes me feel pretty stupid for not having personally verified that it was correctly working when I posted back on the 6th.