DT was also held on a long pass attempt from Lynch.  If that pass had been complete everything about Lynch's performance would look different.  

Siemian is a career backup, and I like the guy.  But he is never going to win games for the Broncos.  We need to find out if Lynch can win games for the Broncos, and we need to know, well, actually last year (but Kubiak was more interested in his W-L record than in the long-term health of the Broncos, so we didn't).

Start Lynch, and let him play the entire game, the entire season.  If he isn't the guy, then we know this and can move on.  Otherwise, we waste another year of 8-8 (or if lucky 9-7).  We need to find out if Lynch can win games.  He will probably always be erratic and unpredictable, but that doesn't mean he can't win games for us.