The conviction of a 77-year-old Alta Sierra man who was found guilty of attempted murder was overturned by a judge Friday because his public defender did not realize the man faced a potential sentence of 34 years to life — and therefore did not adequately present a plea offer before his trial. Instead, Morris Hyman will face eight to 12 years after getting a second chance at that plea agreement. Hyman shot Thomas Demes, his stepson, twice from behind after they argued in the garage of their residence on April 28, 2011. Hyman was found guilty in April of this …