"I can confirm that."
Translation:Das kann ich bestätigen.
I wrote the same thing. Technically, what we wrote is "I can confirm IT" rather than "I can confirm THAT". In English, the two sentences are practically interchangeable, but maybe in German there's more of a distinction between "it" and "that". (Or maybe the owl is just being picky.) Hopefully a native can weigh in.
FWIW, I've been dinged for writing "es" instead of "das" in other sentences, too.