"That is what a sorcerer is, where I come from. A demon, which cannot exist without a physical form, bonded to a human. So Desdemona is sharing mine," Penric explained. "We've been together for nearly half my life at this point. And normally I'm able to use the chaos she generates in a more controlled fashion."

He's framing it as 'I' out of habit, because the word for a sorcerer whose demon is in control is 'possessed' and people are usually more comfortable with a human face. Though... this woman might not be human, even if she is obviously a person. That and while Penric has memories of his childhood as a perfectly normal human, Des developed the control of her powers as part of becoming a person. Losing parts of her is far more distressing, so Penric could shoulder the blame of the accidents.

You know I can hear you think that, Penric, Des added. But I do appreciate the sentiment.