When questioned, Major Green states that he does not know the Doctor and that he has no memory from the time he was under Wotan's control. However, he met the Doctor before being hypnotized by Wotan, so there's no reason he shouldn't know the Doctor.
When the Doctor, Ben and Sir Charles enter the workmen's tent, it is only just taller than the three men, all of whom have to duck to enter. The internal shots, however, have a couple of feet of headroom.
As the soldiers discuss the plan to capture a war machine, the backcloth depicting trees behind the captain is wrinkled.
When Brett tests a war machine, the machine's operator can briefly be seen through the grill just below its number.