When the Cat Priest gets up and has a heart attack, the hat he is wearing falls onto his face when he falls back onto the bed, yet in the close-up of him lying dead, there is no hat visible.
When the capsule is brought on board, the top of it is covered with dust. While there may be some intergalactic dust in space that would coat the capsule, there wouldn't be any "top" for it to accumulate on. Rather, it should have received a very light "dusting" over its whole surface, if at all.
The pyramids of ancient Egypt were built by farmers during the flood season not slaves. This has been documented by written records and graffiti found in structures in the Giza complex.
When Holly is explaining to Lister that the Cat's people fought over whether their hats should be blue or red, the picture that appears on the screen clearly shows both sides wearing red hats.
After the Cat Priest collapses back onto his bed and dies, he shifts his right foot.
When the toaster is asking Lister if he would like toast, in the following conversation, you can see a crew member's legs reflected in the toaster.