I think we are forgetting something. The only reason Jay went in the building is because he saw Tim running out. Meaning the building was now open.
How did Tim get inside?
He is obviously wearing the camera harness (note the 2 dots on his back) meaning he was filming.
I want to see that footage.
Now, this is simply conjecture, what if while Tim was roaming around he found Alex in the chair where Hoody left him. What if Tim, being a nice guy, released him. What if the reason Tim is running away in a panic is because the newly released Alex disappeared and he realized that he was going to need some backup if he was going to continue his search.
What I’m saying is, what if it was Tim’s fault? He thought he was doing good by freeing a friend but it only got his other friend shot.
Just something to think about while we wait for the next installment.