Jut finished my first play-through, v hard, non-lethal. Succeeded on all bar Flooded District, where I apparently killed 1 hostile (not Daud) - accidentally via rats I guess.

My question...can I replay just that one mission (non-lethally this time hopefully) and get the Clean Hands trophy/achievement, given my success in all the others, or do I need to do from that mission on? I wasn't in the mood to restart it at the time. In fact, I thought "s*d it, I'll play lethally from now on", only to discover that I couldn't as the non-lethal approach was so ingrained.
If it's the latter, I won't bother tbh, I'm going for a distinctly high chaos approach next time.

Thanks.