"Too many of Siemian’s passes seem to be made by a quarterback with one eye cast downfield and one eye over his shoulder, as if he also believes the Broncos are looking for any reason to give the starting job to Lynch."

Well, gee, Mark.  Aren't they in truth looking for any reason possible to give the starting job to Lynch?  Isn't that the same drum you've been beating since Romo unequivocally retired?   So, I'm guessing you've accepted the fact that maybe Lynch isn't the second coming.