Visible crew/equipment: When we see first Kate open a door, it opens, and she leaves her hand up, then slowly lowers it. Look to the left of the cube-shaped doorway, and you can see in the room behind her, the edge of a stand or table or some equipment, which obviously shouldn't be seen there.
Visible crew/equipment: At one point when everyone is escaping through the doors away from the moving wall, when Simon is the last one to climb through the door. When the door closes we can see a persons arm reflected in the door. That is an impossible position for any of the others to stand in, so it has to be a crew members arm.
Visible crew/equipment: After solving the "60659" mystery, Kate opens a portal, revealing nothing but darkness outside it. It then cuts to a shot of the watch ticking, then back to Kate who is still kneeling down. In this shot you can clearly see down her blouse, and the long black mic wire and mic is very visible.
Visible crew/equipment: When Julia and Max are talking about Alex Trusk, Max then goes on to tell Julia that he designed the concept for the variable time-speed rooms. As he walks across the room, exclaiming "It was for a game! Now here we are!", watch the floor to the right of the screen, and you can see some black crew equipment laying there, which is nothing that belongs to Julia or Max.