A state appeals panel has reversed the felony murder conviction of a defendant who shot and killed his ex’s current boyfriend.To convict on felony murder, the state must prove the defendant’s attempt to commit a forcible felony started a chain reaction of events that led to a person’s death.Defendant Antwan Space was indicted for the Aug. 9, 2002, shooting in Douglas Park.Space shot Mitchell Barrow twice. While Space’s gun jammed, Virgil Thomas tried to help carry his cousin Barrow away. Space then …