Dealing with Alistair is an inevitability that Loghain can't avoid, and the part of him that owns his (world-changing, life-altering, beyond catastrophic) mistakes knows that he wouldn't choose that option even if it were presented to him. No, he won't turn his back on his shame, and he won't foist the task of handling it off onto anyone else, either.

He lets Nathaniel's commentary about Alistair slide off his shoulders, waits for him to ask for his report. And then he provides it.

It's short but sweet, and accounts for his absence from Weisshaupt during the events that led to the Wardens' coup in the Anderfels. Loghain had heard the false Calling as well, and had devoted most of his energies to evading the old Warden-Commander's Venatori agents as they hounded him across the Western Approach. When he'd heard about the coup, he'd ventured back long enough to verify for himself the Wardens' actions--and then he'd left, to come here... and to kill as many Venatori as he could on the way. On foot or on horseback, it was quite the long journey, and he met with some delays while struggling through war-torn Orlais.

When he lapses into silence, it's clear that he's finished. He sits quietly across from Nathaniel, considering him pensively.