I understand Frost has said to his players that they should have "no fear of failure", but that is really meaning that they aren't going to get yelled or screamed at for making a mistake.
Regarding Frost, he reached a point where he had to try to be "smart" against Iowa, call more conservative play calls, and go for OT. He was burned by an Adrian turnover at the end of the first half which cost NU points. At 2nd and 20 with under a minute remaining, it was the right decision to go for OT. However, it was poorly executed, which Frost admitted after the game.
IMO, the biggest things Frost needs to improve his coaching are: fixing the special teams, game management, and getting the team and coaches to do the little things correctly. Those areas have been killing NU in close games and are a reflection of coaching.