娘の気持ちも知らずに、いや、知っていて、平気でそんな風に言えるのがヒロシだ。
The one speaking with indifference like that, without understanding his daughter's feelings, is Hiroshi.
My translation doesn't include the いや、知っていて part. I'm struggling to even guess what this means. Maybe "knowing he's being unpleasant"?
I suspect there are a few words/particles missing here, but I can't fill in the gaps.