So far, I don't think the doctors involved have admitted to any mercy killings, nor any other type. And it's possible that is what happened. But if they did - I'm all for ignoring it, so long as the patients were past the point of no return - it really is inhumane what we will do to helpless people once they are in the grip of the medical system.
So - my analysis -
Option 1: The medicine was just to treat pain, no attempts whatsoever at euthanasia (possible error though) - it's horrible that these people are being second guessed when they were heroes to stay there and risk death to care for these people, when they could have left!
Option 2: Some or all of those who died were in fact killed with deliberate overdoeses, but only when it was clear they would die anyway, and in horrible conditions, pain, unable to communicate or experience anything other than the pain. In this case, I'm all for a wink and a nod - if we have to, pretend it was an accident - or one of them can stand up and fight the unjust laws that would have condemned these poor people to torture before their death - but I wouldn't expect them to - they've sacrificed enough. I know if I were in the situation, seeing someone in pain and lousy circumstances, knowing they were going to die after more pain, and nothing at all, not even a hilicopter at the roof that moment could stop it - I'd be right there to give them a mercy injection to take the pain away, permanently.
Option 3: Overdoses were given prematurely, or to stop the screaming when it was too much for the nurses or doctor to bear. OK, that's a problem, but in the situation, they're definitely not hardened criminals, just people in an impossible situation doing what they could. Assuming there's no previous similar issues - probation at worst is all I could support.
I think it's probably option 2, but it sounds like the defense is going with an option 1 scenario as their story - which is plausible, and so long as those who died could not be saved - I don't care if that's a cover story for option 2.