Hill vs Siemian why is there a debate?

This^ was the impressive part for me. Mentally he wasn't overwhelmed by having to come in and direct our offense. This (to me) is proof that he was prepared to lead the team even though he didn't get the kind of reps that he will get in practice this week. Whether starting or not, I trust that he will be even more prepared this week if/when his name is called. It was a tough situation to come into this past Sunday and he certainly handled himself well. I'm not convinced he won't start or see some opportunities against Atlanta this Sunday. We all know how Sean likes to rotate QBs to keep the opponents off balance. It'll be interesting to see what transpires this week.
I was a little shocked when his first snap was a pass.