She knows why he's doing this. He has a very grudging respect for Marcone, and his overblown sense of chivalry won't let him not save Lara Raith.

Still.

His brother's death is utterly unacceptable.

She has watched them, through Harry's eyes, and knows this. To quote Lara, she knows either of them would rather rip off their right arms before seeing the other hurt.

She cares for Harry, and Harry cares for Thomas. That makes the choice much easier.

Huh.

Look at that.

She made a choice.

Her choice.

She holds onto that, and doesn't regret it for a moment.