The Sun Makers:
|ep 1 –||When the Doctor is playing chess with K-9, the move he makes is illegal — he moves his queen to Queen 4, even though this exposes his king to check from the black queen. Then, when K-9 replies with "Queen to Knight 6," the square Leela moves the queen to (which K-9 confirms is correct) is actually Bishop 6.|
|ep 1 –||When the Doctor and Leela exit the TARDIS, the Doctor goes to leave first while Leela talks to K-9, but in the exterior shot Leela is the first to exit the police box.|
|ep 1 –||The Doctor calls Pluto a "lifeless rock", although "lifeless snowball" would be far more appropriate: Pluto is mainly composed of ice (though it does have a small rocky core).|
|ep 1 –||The Doctor offers Cordo a "jelly baby" and eats one himself — but it looks remarkably like a liquorice allsort.
[Something similar happens again in Part 2, when the Doctor offers a "humbug" to the Gatherer, which is clearly seen to be a jelly baby. However in that case I'll count it as deliberate since the Doctor is presumably using "humbug" as a pun, i.e. he knows he's being lied to]
|ep 2-4 –||In the Correction Centre, the PCM control centre and the Collector's chamber, the backdrops behind the tables and on the walls are actually metallisation photos from memory chips made by AMD (Advanced Micro Devices, based in California). In several shots the word "AMD" can even be seen (often out of focus, but quite clearly visible behind Cordo when the rebels take over PCM Control in Part 3).
[Apparently those in the microchip business find this rather amusing]
|ep 2 –||The cameraman stumbles and shakes the shot as Leela is confronting "the Others" with their cowardice, just as Mandrel says "They've got things called guns, and what have we got?"|
|ep 3 –||Leela asks K-9 to "get" two guards that arrive in a transport vehicle. After shooting the second guard, a close up of K-9 shows his nose blaster fully retracted. Then the camera cuts to a shot of Leela, K-9 and two others, whence you can see K-9's nose blaster fully retract again.|
|ep 3 –||Mugshots of the Doctor and Leela are flashed separately on viewscreens throughout the city, seeking the capture of one and announcing the impending execution of the other. Perhaps the picture of the Doctor could have been obtained by the city's scanners when they were set up to track him. But where did the picture of Leela come from — without the wound on her forehead? She wasn't known to the authorities until after being shot.
[And if you think the photo might have been taken in the hallway before her capture, think again. There were no scanners there, even though they're supposedly placed "everywhere" in the city]
|ep 4 –||In the Collector's chamber, Leela throws a knife at the guard holding a gun on the Doctor. The guard has his back to her, but the knife somehow lands on the front side of his shoulder.|
|ep 4 –||In the final scene, as the TARDIS console room supposedly tilts, the string used to pull the hatstand over is very visible, and in the next shot it comes drifting back into the right-hand side of the picture. Also, the electrical cable running from the console to the back wall of the set is horribly obvious, being a black cable on a white floor!|