Dr Bullard says half of Henry Hammond's head has been blown off. But the left side of his head shows only the one small bullet hole, and later in the coffin it can be seen that the other side of his head is also intact.
The machine gun bullets would have torn through the victim. The are no holes in his back as he is being shot.
To make the bullets track across the ground as depicted, the machine gun would need to raise its elevation as it fired. The view of the gun showed it staying level as it was firing.
Electric wheelchairs use a mechanical switch to activate and control the wheels. To rig the chair for remote control would take a complex control system to be added to the chair, not just a radio control unit.
The machine gun would have needed someone to 'fan' the weapon to create the 'stitching' of the bullets on the ground.
When the "soldiers" are on parade in front of the Hammond home, rain is pouring down. But it is also obvious that the sun is shining brightly, revealing that the "rain" is being produced artificially by crew. The same can be seen shortly afterward at the home of the Barnabys.
The Union Jack on display in the Hammond mansion is hung upside down.
The shots of the rear of the Sperry+New Holland baler are reversed, showing the output chute on the right side of the implement. They are on the left side.
During the flashback the murderer is shown setting up the machine gun with bare hands. Why didn't fingerprints reveal the killer's identity to Barnaby?