When Arthur and Kara meet in the woods she says that she ran from her master and she is lost, but moments latter she says that she knows the place and the plant that Arthur is looking for and she can show Arthur where to find it. Arthur does not appear to be quick enough on the uptake to catch the change, though.

Continuity Gaff: After Arthur kills the cockatrice with his long sword, as he enters the cave with Nimueh, he does not visibly retrieve it from the body of the cockatrice, nor is the handle visible in its scabbard on his left side (his short sword, on his right, is visible). When the spiders come out, he pulls his long sword again, and there is no question it's his long sword, since when he sheathes it after, it is sheathed on his left side.