Other mistake: The tree used to hold up Number 2 is very thin and weak looking, yet it supposed to be supporting a 400lb robot. Strong tree. (01:13:25)
Other mistake: During the shot where Newton and Stephanie first argue ("did you say the the robot drove the truck?") in the background Number 1 is missing its treads, leaving the idler wheels and internal chassis of the robot's tread mechanism exposed. (00:45:05)
Other mistake: When Johnny is changing his arm in the back of the Nova truck, it's quite obvious that the new arm he 'attaches' isn't realy attached at all. (00:51:50)
Other mistake: Newton Crosby (the programmer for the robots) is at the Vista house and Stephany is in Astoria. More than 113 miles (2 hours) away and Stephany is calling to meet up with Crosby to talk about number 5. I don't think 2 hours passed before they met up. All this happens within 5 min. Not to mention how did Crosby get out to Vista house so fast?
Answer: There were always 5. You see the 5 during the demonstration. Then, before the lightning hits, we see 4 of them in line, but number 5 was still attached to the generator and not in line. When they go inside, there's a weird cut that makes it look like only 3 made the turn, but if you watch closely you can see there's 4 followed by number 5.
Bishop73