To me it is very simple. When Oromagi was town, ge reacted to being scumread by me far more. He also offered consistently positive feedback. When Press was town, he kept interrogating everyone, never once 'pushing back on those who suspect him' even when he was uncc'd miller and their suspicions made no sense. This game he's not just scummy in itself, he is behaving very different to before, much more 'waa waa you scumread me' and much less 'everyone, I am onto you!'
Oromagi and Press are scum, I am getting more certain over time.