Some people really over-reacting on Kaep.
If Alex was in, yes I think that those mistakes wouldn't have happened and he would have eaten the sack, but on the other hand it was not a safety but a very bad call by the refs. Kaep is a rookie really, he's just started this season in live games which is a big difference from being backup for one season.
However, look at it this way:
1) Refs make the right call on the "safety" and there's no tie at end of regulation time.
2) Walker catches the TD pass and we win.
3) Akers kicks one of 2 missed field goals inside his range and we win.
Those are three definitive collaborations to the cause but beyond that:
1) Horrible, horrible play calling - Roman seems unable to adjust to the game live.
2) Staley holding call killed our 3rd(?) drive in the 2nd quarter taking us outside FG range at the least.
3) Walker holding call killed a drive
4) BS personal foul call on Goldson when he was making a legitimate hit on Bradford which moved them into FG range for the tie.
5) Goodwin is getting blown away at centre a lot, seems to be a huge number of plays coming down the middle where he loses his man inside 2 seconds. He was responsible for a lot of that pressure on Kaep.
The only genuine errors Kaep made were poor execution on the lateral to Ginn (we all agree it's a horrible call in that situation) and running out of bounds on the last 4th quarter drive when he should have kept the clock running,
Now having said that, it's easy to blame a rookie for rookie errors, especially when he's the QB and there's a controversy on his selection, however a number of experienced, veteran players and coaches made some very costly mistakes which made a significant impact on the end result.