Stupidity: 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.
Character mistake: When Barr denies giving Jeff's wife a ride, Jeff says this was in the last half hour or so - but considering the time it would take the truck to go to Belle's (5 miles away), the wife to call a tow truck, back from Belle's, then Jeff waiting extra time, then fixing the jeep, heading to Belle's, the time he spent inside, then driving along the road until he saw the truck would in no way be only a half hour...more like an hour or two at best.