There was also an "Enter" rune on the church that Datu saw. They did not take a picture and it may no longer be there.

There are a lot of great points here. I will do my best to think outside the box, so we can avoid a group-think lock up. Even if five people agree on the evidence, someone should always serve as The Devils Advocate...

I am not sure if the biters took Datu and the others so they could be turned. They could have been taken as hostages. That way ink and crew could kill off the rescue parties. Attacking from a defensive position is better than assaulting someone else's.

When Kalani first gets there, he meets the guy with the drugs. I am ashamed that I do not recall at the moment. In my mind, the drugs link him back to Tardust more than CJ's Tower.

Maybe Randy did mark Datu and Saul so he other biters would leave them alone. However, if Randy cannot talk, maybe he marked them to says "Stop That!" it's our water, or stay out of my house!

We are still left with the gas having different effects on different people. Some cough, some change, some seem immune, maybe some of the first people at ground zero just died. However, the first news reports were rioters attacking people. Not a lot of people coughing.

I am still left with the concept that the gas is a defensive counter measure creating an area of denial. Humans were Fracking in Ingelwood. The gas caused them to stop ( among other things) Gunfire at ground zero and the gas comes back. People invade the tunnels and the gas comes back.