I think the defence has scored a huge own goal. The string of witnesses testifying that they accidentally wander into each other's apartments does her no favours, quite the opposite IMO. What she should have done was what the rest of the tenants probably did; had a little look around, realised she was in the wrong place, apologised and left. Even if she was in her apartment and there was someone else inside it could have been anyone, the maintenance man, a friend or relative dropped in to surprise her, fire dept checking something out. But no, she goes straight to "I'm in fear for my life, I must shoot to kill." Her defence is ludicrous.
It's easy to excuse her actions by presuming she must have some kind of psychiatric or emotional condition but there is no testimony for this so we must presume that she hasn't.
My dad was a police officer for nearly 40 years, was almost killed more than once. I think I was 4 years old when I realised that every time he went to work might be the last time I saw him. He policed the poll tax riots, the race riots 1981 and many more (if you are not from the UK or not familiar with these events, look it up. It was brutal.) He once didn't come home for 5 days and 5 nights, my mum didn't even know if he was alive. He would come home from the most difficult, soul destroying shifts and lovingly tuck us into bed. Not once have I ever seen him raise so much as his voice in aggression, let alone a weapon. Being a police officer is no defence, in fact IMO it makes it worse.