In the beginning they always run to the side. NOT down the tunnel that is opening all the doors. I know it was probably for ease of production but have they ever mentioned it?
the doors are for cambot!
They have used the theater doors at several points. The most notable point was when the bridge door got stuck in Soultaker and Mike had to open it physically, then started running down it with Cambot chasing him.
There seem to be more convenient entrances to the theater for everyone else. There was an episode early on where Joel jumped down a chute on the bridge to get into the theater, but it escapes me as to which episode it was.
I’d like to think they’re just getting out of the way so Cambot can go first, then they follow behind him, possibly so they can psych themselves up, do deep breathing exercises, whatever prep they need to survive the next leg of the experiment without the Mads getting the satisfaction of recording the data.