Towards the end of the Beaumont party scene, Alex and the security guys are in the hallway with the killer statues. One of the security men falls to the floor and his earpiece falls off. Throughout the scene, it keeps changing position from being on the floor next to him, to back on his ear, to being on his ear in a different position.
After the explosion in the laboratory, Josh is laying on the floor, injured. His face is covered in blood, however during the scene the amount of blood on his face keeps changing. In close ups of his face his lips are free of blood, but in wider shots his lips are covered in thick amounts of blood.
Security is trying to help Alex escape. Each security guard is using a semi-automatic pistol, and when the clips are empty, the gun is heard to be making a double click sound. No semi-automatic pistol will make a double clicking noise when the slide is drawn back, as these are shown to be, when the clip is empty.