Is this really the first time ...

[Xandro]

... that Redcloak made a miscalculation ? ? ?

Reddy thought, that the non-execution of the human slaves would give him positive P.R.. Perharps he is not Lawful Evil but Lawful Neutral like it was already suggested and he doesn't like killing if it is not really necessary.
Perharps (like I suppose) he is only pragmatic to the bones and tries to get rid of the main problem of his new city, the human resistance by increasing the their acceptance of his rule. It's a good deed to solve a problem that encumbers his evil plans (so he's still Evil).

In any case, Reddy is miscalculating. His deed isn't aprreciated as good so he gets no P.R. and on the other hand the admiration for the palladin increases the will to resist of the human slaves.

I think it's the first time something like this happens. Till now this goblin was the maker of plans and every time he took over command he succeded. All of his tactical decisions in the battle of Azure City were right and I can't remember any situation where one of his plans failed.

Do you agree? Or am I wrong at some point?

[Chronos]

No, Redcloak is definitely evil. There are some things he's done (particularly in Start of Darkness) which you just can't do and remain neutral. However, just because he's evil doesn't mean that he has no moral limits whatsoever. It may be that we've just seen one of those limits: Deep down, he's just not quite evil enough to destroy souls. He probably doesn't want to admit this to himself (the Plan he's undertaking carries the risk of destroying the soul of everyone in the world, and he's stated that he considers that an acceptable (though suboptimal) outcome), so he makes up some nonsense about releasing the prisoners for PR purposes instead.

[SPoD]

In addition, Redcloak makes some pretty major miscalculations in Start of Darkness as well. He's not infallible.

For those who have read it, I'm referring to...
...thinking he could control Xykon by threatening the phylactery.

Or, for that matter, using Flame Strike on a treant in the middle of the forest!