What was Niners Coach Nolan thinking?

Can anyone tell me how Mike Nolan got his job? 2 of the challenges during the Eagles/Niners game were so stupid. Why would you challenge a field goal, A FIELD GOAL, if he had a brain in his head, he would realize that a field goal is not a reviewable play, and his other challenge, where Jackson was clearly inbounds...and btw I am an Eagles fan, diehard for 25 years