Visible crew/equipment: When the Muslim armies approach Brendan Gleason's castle there is a side shot of the Muslims army coming to a halt. You can see the marker stake with yellow tape at the top (used during production as a mark). (01:10:10)
Other mistake: At Kerak, as the 2 armies are facing off, the wind is blowing the banners of Saladin's army hard to the left, but as the view switches to Baldwin's army, facing the opposite direction, their banners are also blowing left. (01:33:00 - 01:33:50)
Answer: I thought it was cotton with oil of clove for a bad tooth.