The Android Invasion:
|ep 1 –||While the Doctor and Sarah are walking through the forest (right after they leave the clearing which the TARDIS is in), the Doctor pulls a branch out of his way. Lis Sladen isn't paying close attention and is in the middle of her line when the branch flies back and hits her in the face. You can tell she was stung a little (or a lot) because she gives a little squeak but manages to finish her line.|
|ep 1 –||The Doctor's scarf gets caught in the bushes and branches while walking along with Sarah, and Lis Sladen clearly laughs out of character.|
|ep 1 –||There's a scene where the mechanics are shooting at the Doctor and Sarah, and they dive for cover behind a "meteorite". In the shot when they later run for it, you can see a tarpaulin spread behind the meteorite — which wasn't there before!
[Presumably it was put there so cast wouldn't get their costumes dirty when they dived for cover]
|ep 1 –||When the Doctor arrives at the Space Defence Centre, he asks a stony-faced android guard where the commanding officer can be located. The guard obviously has his pause button pressed, and is unresponsive — except for an uncontrollable blink as Tom moves away.
[The actor looks duly abashed]
|ep 2 –||When the Doctor plays darts, he hits three bullseyes. But if he's that good at darts, surely he'd aim for higher-scoring triple 20s instead?
[For the non-darts-players among you, a triple 20 scores 60 points, compared to "only" 50 for a bullseye]
|ep 2 –||Speaking of darts, watch their trajectory as they hit the dartboard (especially the second one). It's obvious that they were pulled out of the board and the tape run in reverse!|
|ep 2 –||Why does the android Sarah wear a scarf, thus tipping off the Doctor that she's a fake? The real Sarah wasn't wearing her scarf when she was captured, so why would her duplicate be created with a scarf?|
|ep 2 –||The Doctor throws the android Sarah to the ground at the episode's climax, and her face plate falls off to expose her electronic innards. The fake hair adorning its head is appallingly obvious, being a completely different texture and shade to Elisabeth Sladen's own hair.|
|ep 3-4 –||In the rocket, the Doctor pulls one of the androids out of its container and dumps it on the floor, so that Sarah can use the container as protection against the take-off acceleration. However, as he's moving off, Tom Baker discovers that he's managed to trap his scarf underneath the android. Not to worry, though — the actor playing the supposedly deactivated android helpfully lifts up his arm so that Tom can free the scarf.|
|ep 3-4 –||The rocket take-off is obviously NASA stock footage — not only is the rocket shaped entirely unlike Crayford's one, but we can even see "UNITED STATES" on its side as it slowly rises past the camera!|
|ep 4 –||When the Doctor comes through the automatic doors of the real Space Defence Centre for the first time, they slide open, but don't quite close. The poor souls in charge of making them slide don't even notice!
[The resulting gap could have devastating effects on their air-conditioning bill...!]
|ep 4 –||When the Doctor talks to Harry and Colonel Faraday and convinces them to come back to the Space Centre, keep an eye on the cord of the microphone he's holding as he finishes and turns back to talk to Grierson. The cord suddenly starts swinging around for no apparent reason — obviously accidentally jostled by an out-of-vision stagehand.|
|ep 4 –||Look at the unconscious Benton in the scene where he is replaced by his android replica — he's blinking uncontrollably.|
|ep 4 –||In the fight scene between the Doctor and his stunt double android, the wig choice for his double leaves a great deal to be desired, looking more like a Kevin Keegan perm than Tom Baker's distinctive mop.|
|ep 4 –||When the Doctor's android double is finally destroyed, its skin disappears to reveal the metal skeleton beneath. What's problematic is that the skeleton is clearly larger than Tom Baker's face; watch his left cheek in particular.|