Continuity mistake: While sitting on the bench, near the lake, when Grandpa is telling John about out living everyone by eating bacon and smoking everyday, he has a cigarette in his left hand and a beer in his right hand. After a few minutes, when it switches back and forth from Grandpa to John, the cigarette and beer switch hands and then back again, between shots.
Continuity mistake: When Jack & Walter drive to the fishing spot instead of the wedding, the exterior shots of the car show the Dodge Polara as a 4-door pillarless hardtop. When the interior of the car is shown, it is a four-door sedan, showing the thick pillar seen behind each man as they converse. As they speed back to the wedding, the four-door sedan now appears in a couple of exterior shots, and now the hardtop is used during interior shots of both men through the windshield.