Other mistake: In one of the first scenes in the study, Mr. Boddy hands each guest a weapon and then proceeds to turn out the lights. The room is thrown into complete darkness. Unfortunately, there is a roaring fire in the fireplace that would have illuminated the room enough for everyone to see what was going on.
Other mistake: During a scene shot on the bridge, you see two vehicles pull up - later you see that another vehicle has arrived with reinforcements in an aerial shot. At this time, you see a man firing a automatic weapon, and then one of his fellow soldiers crossing directly into his line of fire, but the man is not hit.
Other mistake: When Morris is chasing the ambulance on his bicycle, he gets pushed/bumped towards the picnic table. As he tumbles over the table into the water you can see handle bars attached to the bicycle, however whilst Morris is flying through the air (separately to the bicycle), he is holding a second set of handle bars in his hands. (00:42:50)Mr Manchester