IIRC PC drives a cement truck, if true...he is hauling wet cement that has to be delivered to whatever job site. He may have already made his last delivery at that time & just was releasing the load perhaps (which is not as easy as a dump truck & has to be cleaned out as well at the end of the day). Also IIRC he came home around 5:30 & picked up the twin to go out & search.
Honestly I don't see anything wrong with the time line with Mom or BF & I do fully realize the statistics with a missing child and everyone has to be looked at carefully especially family. There is a few things I find hinky but...I am want to squash my (those) thoughts for the time being.