I agree. While Meredith's actions in that regard can't be excused (stopping the nobles from electing a new Viscount because she's afraid they will choose someone who may stop her is not lawful at all), I do think Lambert was honest in his decision.
Too honest, in fact. And too blinded and probably naive. I'm beginning to suspect that he was a victim and also an unwitting pawn in this large conspiration hinted by the promotional material about the hidden villain in Inquisition.
Hrm to be honest i hadn't considered him nor Fiona to be the overt pawns of a puppet master to be honest.
The situation needed to be pushed in that direction certainly for whomever is pulling the strings, but i think ultimately the actual tool in question? Was Either Adrian or Rhys. Think about it, A Demon magically manifests to him, one of the few capable of cognitive thought process with out breaking out in tangents to posses some one? Or A Murderer who forced both factions to the final straw that resulted in war.
Either one to me ultimately seems like a far more likely puppet who subtly or overtly pushed things to war in the conclusion of Asunder, but that said the Dev's haven't stated any one from DA has been under the influence of this being as of yet, In fact the person in question that could be either the pawn or puppet master could appear within the Masked Empire, as people are speculating over the apparent peace treaty at the beginning of inquisition i have a feeling that whomever moves to sabotage said process likely will be backing the group or entity behind the veil tears.
Because personally i think that given Lambert or Fiona's position, their politics and etc moving those pieces into place would have been a project of decades if not longer. I think we are dealing with something a bit more short term.