I have no idea where you got this. Verdis Elementum has always had the stance to ignore Sanguis Astroism. There never was any call for arms against SA in Verdis Elementum channels, nor any message about justifying any looting act.
If some low-ranking nobles invoked it to justify their actions, then in no way can you extend this to the religion as a whole. I'm not even sure if any of the VE elders were even members of Caerwyn in the later days...
There were some messages passed around in Caerwyn, that got passed along to Astrum, about Caerwyn claiming they were using "secular means to fight a religious war". I don't remember the exact content or context of them. Caerwyn's government was also heavily backing VE as a shield against the encroachment of SA, and officially endorsed it.
Whether or not the actions taken by Caerwyn were endorsed or initiated by VE, there is a strong impression that VE was involved. And since Caerwyn specifically was targeting SA, I think it's pretty natural for people to place blame on Caaerwyn's religion in turn.
Having said that, I don't think too many people in SA really care about VE, now that Caerwyn is dead. Vengeance has been delivered.