For example a neutral evil, lawful evil, true neutral characters could still side with the Absolute only because they could see this as a chance for cure (I will not give spoilers why, unless asked to do so), but they absolutely wouldn't just decide to slay everyone in the grove.
Last time i tryed (patch 2) there was option to "miss the raid" ...
It was simple, you send Minthara with her Goblins to attack and then simply long rest few times not caring about it ... then once you wake up, your questlog update to "the groowe was destroyed before you could do anything about it" or something like that.
Thanks for letting me know, I actually could try to test it right now in the Patch 4, as I have plenty of saves. When I'm done I will upload some screenshots and post them here, to check the results. But, still if we want to side with Absolute for power/possible cure and do not slaughter everyone, that's still not possible to do .