Let's see:
-I killed Zuben as he charged McCoy at home.
-Didn't kill homeless guy.
-In act 3, I killed replicant Gordon, warned Lucy about Crystal, then killed replicant Dektora.
-In act 4, I VK a human Lucy, then let Clovis kill Guzza.

And yet I ended up in Act 5 with the replicant sympathiser path. AFAIK this shouldn't be the case if I killed Zuben, right? Is there a bug in the works?
I'm using the base GOG version.Can't seem to be able to attach the savegame, I get "Wrong file format!".

Killing Zuben will make the Replicants angry with McCoy, but it won't prevent McCoy to act as a sympathizer later on and win the favor of at least some of the Replicants iirc. I also think that if you kill Zuben when he ambushes McCoy, it's a special case because at that point McCoy has no other choice but to kill him, and also there's no Gordo around to pass the news to the Replicants (I may have to check with the engine code to confirm this though).

With the exception of Lucy, you did do a lot of Blade Runner stuff, though, so it could be worth looking into this.

Which sympathizer ending did you get specifically?

Could you upload your Act 5 savegame on a Cloud service (eg. a public shared file on Google drive) so that we could check this?

Sorry to keep you waiting, I'll try to look into this as soon as possible. I'm in the process of moving to a new location and things have been extra hectic the last few weeks.

It could be this weekend, or it could be in a few days from now. I'll post here the moment I have something new on the issue.

No problem, take as long as you need, and good luck moving.

Hey, sorry for taking this long to respond.

So, I have some findings.
From the code itself, and based on the events that I can gather that occurred during your playthrough, from your description and the save games you shared:
- It seems that this is an allowed path. McCoy basically gains Lucy's trust by warning her about Crystal and, later on, this can result in a huge bonus of favor from Clovis towards McCoy (even though, he will still instruct Sadik to kill McCoy in the underground meeting, after Guzza is dead, if McCoy has killed no human).
- So starting Act 5, the game decides based on who favors McCoy the most. Clovis or Steele. And in this case (of your saved game) the answer is Clovis, mainly due to that huge bonus. Probably also due to missed opportunities for actions that would increase Steele's favor for McCoy significantly. I can see a few such actions (like McCoy could pick up the suitcase that Guzza leaves in the underground meeting (pixel hunt!) and deliver it to the police to exonerate himself) but there should be more in the course of the game (that one by itself is not enough).

Now, this could still be a bug. I'll have to investigate further. Because it's either intended to leave this possibility open even if McCoy was largely a proper Blade Runner, or the game fails to account for certain events properly in this path.

Oh hi! I just read this. Glad you were able to find the time to look into this.
It's interesting how much warning Lucy determines the game's ending, in my case. I do think I missed many little actions, it was my first run!
Let me know if you find anything else.