Before the dog Zeus charges at Mac and Merlin, no rope is visible; however, the rope is anchored to the cave wall in clear sight when they are confronting the animal.
MacGyver is able to read Morganna's notes about the gunpowder, but MacGyver probably would be unable to read the old fashioned script. Of course, he shouldn't be able to even understand what they say, nor should anyone be able to understand him.
When MacGyver was tying the quills together and Ian's body lying on the floor and supposed to be dead. You can see that he's breathing cause his stomach rises then goes back down.
The prisoner writes on the wall "Walk in love, walk in service, and you will walk in honor". These words would not have been written like that and they wouldn't have been chosen in the time of King Arthur (ca. 600). In those days, people spoke Common Britonnic.
Morgana uses the word "machine" (her killing machine), yet in part one of the story, Merlin was unfamiliar with the word, asking MacGyver, "What's a machine?"
When MacGyver and Merlin are caught on the trap door in the cave and MacGyver tells him he's going to swivel around on the pivot point, Merlin shouts out about both words in a confused tone saying, "Speak English!", yet later in the episode he knows what a pivot is when holding a pair of scissors.