Are Stand Your Ground laws applied unevenly?

Marissa Alexander, a 31-year-old woman in Florida, recently received a 20-year sentence for protecting herself against her abusive husband.

Says Alexander: [Gray] assaulted me, shoving, strangling and holding me against my will, preventing me from fleeing all while I begged for him to leave. After a minute or two of trying to escape, I was able to make it to the garage where my truck was parked, but in my haste to leave I realized my keys were missing. I tried to open the garage but there was a mechanical failure. I was unable to leave, trapped in the dark with no way out. For protection against further assault I retrieved my weapon; which is registered and I have a concealed weapon permit. Trapped, no phone, I entered back into my home to either leave through another exit or obtain my cell phone. He and my two stepsons were supposed to be exiting the house thru the front door, but he didn’t leave. Instead he came into the kitchen that leads to the garage and realized I was unable to leave. Instead of leaving thru the front door where his vehicle was parked outside of the garage, he came into the kitchen by himself. I was terrified from the first encounter and feared he came to do as he had threatened. The weapon was in my right hand down by my side and he yelled, “Bitch, I will kill you!” and charged toward me. In fear and desperate attempt, I lifted my weapon up, turned away and discharged a single shot in the wall up in the ceiling. As I stood my ground it prevented him from doing what he threatened and he ran out of the home. Outside of the home, he contacted the police and falsely reported that I shot at him and his sons. The police arrived and I was taken into custody.

So why did a judge reject her invocation of “Stand Your Ground”, saying she could have left the house?