You didn't know he would try?

[She had said as much, but he wanted to be sure.]

I don't think that's your fault. Hell, I aided and abetted Anders with half of his mage rights schemes. But I wasn't the one who put the bomb in the Chantry that day.

[Much as he wanted to blame himself, when it came down the brass tacks, it was just Anders behind the attack.]

We can't always take the fall for our loved ones.