I have seen Lee sang woo in one of his older films with Lee da hee (Mother and Daughters) and honestly I felt song joong ki looks just like the young version of Lee sang woo from back then
I think Kim Doha taking off his shirt in the Episode 6 preview is real because there is a scar on his back that…
The scar on his back is caused by stabbing from do ha's ex gf brother re-watch again there was a scene where a cop was warning the ex gf brother about wasn't stabbing him in the back enough for you it's shown in one of the flashbacks regarding the case I don't remember which ep but I think it was in ep1-3 somewhere