How is it possible for some people to be burnt completely while others in the same room survive the explosion without any serious injuries? Hard to believe... Also, whose foot was that? 

I think there's more to come and Bertram is not RJ. Bertram is the head of the Blake Association and the file they found contains a list of all members.

I still think that Haffner is RJ. PJ announced on TV that RJ is Bertram just to make RJ contact him. Wouldn't be the first time for RJ to react to something that PJ says on TV...