No way and I'm sorry accidental killing as a consequence of a deliberate attempt on someone else's life isn't like he just punched a guy in a bar who fell over and hit his head on a table killing him. Dark Willow pretty much treats that excuse with the contempt it deserves.I actually think Dark Willow is WAY worse than Warren and her rage against him was completely hypocritical. He killed Tara BY ACCIDENT and she set out to kill Jonathan and Andrew who had even less to do with it. They weren't quite innocents but certainly didn't deserve to die. Warren was a mortal, non-powered human and both of the women he killed were killed by "natural" means and without forethought. This is not to let him off the hook for what he did because he did wrong but the worst any of The Trio deserved is an ass-kicking courtesy of Buffy and some prison time.
Warren would be convicted of second degree murder in the case of Tara and attempted murder in the case of Buffy.
I do agree that trying to Jonathan and Andrew was much worse though.