Almost every program has a turning point. Some are positive, like when Tom Butters bucked conventional wisdom in 1980 and hired some guy from Army who had an unpronounceable last name. That worked out fairly well.
And in 1978, Penn State had a different sort of turning point: it nearly hired Bill Guthridge.
Guthridge of course decided to stay in Chapel Hill where he helped Dean Smith build one of the great programs of all time.
Penn State hired Dick Carter instead. He stayed for five years - Guthridge might have stayed until he retired - and was the last winning coach at Penn State.