Jeffrey Leinen of Calgary was convicted in December 2011 of second-degree murder and aggravated assault in a crash outside the Texas Mickey Bar in Olds.
He was sentenced to life with no chance of parole for 14 years in the death of Nicholas Baier, an 18-year-old student at Olds College, and for injuring another person.
Witnesses testified at Leinen's trial that he had been kicked out of the bar for fighting.
Defence lawyer Jennifer Ruttan argued at an Alberta Court of Appeal hearing in April whether the judge's charge to the jury properly accounted for the possibility that the October 2010 crash was an accident.
In a two-to-one decision, the appeal court ordered a new trial, stating the judge in the original case failed to properly instruct the jury on the legal significance of the panic attack defence.
Note to readers: This is a corrected story. The previous version had Leinen sentenced to 14 years.
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