I've heard that with new QB's the coaches sometimes don't let them audible. I've also wondered who is doing the line calls. If it is Buchner for that and he is making mistakes then the line is paying for them, that could be what he alluded to when he said it was his fault.
The truly frustrating part is that they had checks to the sideline when the box was stacked and STILL ran into it. That's not players, that's coaching. Maybe they were playing a game and thought that they could get them to bail from the look they were showing by using the sideline check, but it didn't seem to ever work.