Corrected entry: Jeff should have just locked Red and his crew in the cellar using the key that Arlene used to open it. Instead he barricades it just so Billy could ultimately get access to it. Had Jeff locked it with the key and then taken the key with him, Billy wouldn't be able to free them. Jeff could have then just called the cops and told them where the kidnappers were contained, and then maybe later Billy could just get arrested.
BaconIsMyBFF
5th Nov 2018
Correction: Jeff does in fact lock the cellar with a padlock and key. Billy opens the lock somehow off screen, either by using the tools present in the barn or using a spare key.
BaconIsMyBFF