Cullen had gone to the Templars at 13 years old, and he'd thought it his own choice, at the time. It had been, insofar as a 13-year-old child was capable of choosing anything. He'd thought he was following the highest calling in the world: to protect those who could not protect themselves.
He hadn't known then of the rot deep at the heart of the Chantry, nor had he the experience to recognize the things that were wrong with what he'd been taught his entire life. Then, at the time when he might have learned differently, he was held prisoner, starved, and psychologically tortured. He'd put all his energy into protecting himself, then, using isolation and anger and lyrium to hold off the fear and trauma.
There were lots of reasons for the way he'd felt and behaved, but Cullen did not feel any of those reasons excused him. His mistakes were his own. He didn't expect forgiveness or understanding for them, though in this case, he might hope. They had been friends once, he and Neria, foolish teenage crushes completely aside. He'd missed her.
"The distinction between Templar and former Templar is not one I generally expect to matter to anyone other than myself, usually," Cullen said. "But yes, I left the Order. I was at Kirkwall at the time of the attack on the Chantry, and resigned my commission soon after."