After Big Jim shoots the picture of his family on the corner table, there is no bullet hole either in the wall behind the picture or in the corner table itself.
Big Jim's injury in opening scene was in right shoulder with a emblem patch on left shoulder and shirt was gray and in the following scene when he runs into Jr and Julia the wound is in the left shoulder and higher with no emblem/patch and the shirt is olive green. Wow how did wardrobe miss that.
In the tunnels Junior gets bitten by a butterfly. Butterflies don't bite because they can't. Caterpillars can, but once they become butterflies, they only have a long, curled proboscis, which is like a soft drinking straw.
When Jim shoots the photo of him and junior as a boy the first shot of it shows a hole in the head of junior and most of the glass from the frame gone. When it cuts to the next scene the bullet hole is in juniors right arm and more of the glass is still in the frame.