Continuity mistake: When BB-8 hears the creature come up from the sand behind him, he stops. Just before he turns around the orange rectangles on the left side of his face to being almost all uniform in shape and size, to now having two big ones on the ends and two small ones in the middle. (00:00:30)
BB-8 Bandits - S1-E2
Revealing mistake: When Rey is speeding across the desert away from Teedo and his gang, the shot of her on her speeder has BB-8 not casting a shadow on the side. In most other shots, the shadow of the speeder has a "bump" on the side where BB-8 is tied to it, except in that shot and a few others. (00:01:07)