I don't think, from the story, anyway, that was any actual claim that she lost consciousness. She simply didn't remember the incident, which on face value is plausible, we often don't remember stressful events.
I don't, to be honest, know why that is an excuse, but that's the weird nature of how we treat drivers. You would expect to walk out of court if you'd not remember stabbing someone. That said, I always assume the court heard more evidence than was recorded in the story. Still, it's not encouraging that she was allegedly ok to make a phone call straight afterwards. It's not reported if the police checked her phone records for the time of the accident or if there were medical reports. The prosecution seems a bit half-hearted. Still, she cried, so all good.
