Other mistake: When Arthur and all his knights assemble on hilltop at night and Merlin tells them all not to forget where the Round Table started, you can see the crew's spotlights reflected on the back of some of the knights' armour.
Other mistake: At the siege of Leondegrance's castle, when they show the knights on top of the siege tower moving to the wall, one knight in particular puts a cigarette in his mouth through the breathing slit in his helmet before crossing onto the wall.
Answer: Sunshine is the name of one of Gueniviere's handmaidens. She is also mentioned in L'morte d'Arthur.