This is why Ive been more and more of a believer in the theory of potentially some shady meeting/deal gone wrong happening in the construction site. This would be the simplest way for Clint to have knowledge of something he wants to hide without being directly responsible. The description of Brians personality in the podcast does make it seem like theres a possibility he could have involved himself in some high risk behaviors. This theory explains Brians disappearance, Clints silence, the dog tracing the scent out the door (ie possibly into a car), etc. It fits so well with so many details which is why it has now become my #2 theory behind an accident in the construction site (which still remains #1 IMO).