SpoilerShow
I know you click the switch, turn and move right to throw a rock or something onto the floor plate and then side step back through the gate and then back into the now open door. However, the gate isn't opening fast enough but the door is closing as I'm trying to step through the gate so there's no way I can get to it in time. In the PC version I may have had the rock in my hand when I clicked the switch which saved some time but I am unable to do that on the iPad. I might not be remembering how to solve this puzzle though. Any thoughts?