A common theme that keeps emerging each time the details of this incident is retold is that Magdalene, through the use of earthbinding, STOPPED Porthos from entering a location and prevented him from attacking.
This theme supports the life-preserving effect of her action. Simply because you, and the rest who opposed the action, deem mining offensive to your cause does not negate the fact that and attack was prevented.
Mining, in and of itself, is not offensive. Even the resulting material is used to DEFEND against attack. Porthos was seeking to stop thakria from defending itself and he admitted that he intended to attack.
In my view, Magdalene acted appropriately within the context of the animist way.
Written by my hand on the 22nd of Springflower, in the year 1173.