Right, and why bother, in that case? If you need a character to be freaked out about the Inquisition on his doorstep, okay fine, make one. But why fundamentally alter Teagan's personality to do so? And yeah...I do get that the Teagan of Trespasser is under an entirely different kind of stress than the sort the Teagan of Origins was under in Redcliffe, and that he might see in the Inquisition a looming menace that is actually collecting more and more power in power in his country even while it ends up more an more under Orlesian influence, which any Ferelden should logically be worried by.
Okay, then, so make him a little pushy, make him worried, but it's not just that. It also seems like they didn't make it clear to the voice actor that he wasn't performing as Roderick again, and they didn't seem to go to any pains to make him look much like Teagan either.
Here's the part that gets to me: Extenuating circumstances can account for his being stressed about this, but Teagan is the one that Fereldan sent to Orlais as Ambassador. It didn't last long admittedly, but it wasn't for lack of him trying diplomacy. His being stressed is one thing. His entirely forgetting that beating down doors and hurling accusations all over the place is not actually the way to get people to want to listen to you, is another thing entirely.