When Álex is leaving the ship after they first met Helena walks up to him, her hair clearly falling over her shoulder. As Álex is talking to Helena the shots go back-and-forth between them and, without any movement at all (Helena's standing very still at this point) her hair suddenly disappears from her shoulder.
At Sylvia's workplace and then again when Alex is walking down the highway, there are brief reflections of otherwise unseen lights, implying they are camera/stage lights the filmmaker picked up.