Well that film set shoot that RK was doing 9 takes didn't get it done, and the dialogue of the actress "why did you lie to me" RK couldn't get into character to say whatever the dialogue was, but he was just silent, I felt by the dialogue of the actress and also the clothing she was wearing was like Madhu's new avatar after marriage and what scene he was shooting was similar to what he is going through with his wife Madhu.
So the CV's were trying to show RK was feeling some guilt and when he got home he said he was angry and unthinkingly spoke harshly, apologised for using her to get Sultan arrested, however he also said if he told her she wouldn't have let him do it, so he still thinks getting Sultan arrested was the right move, despite what Madhu said to him that because he got him arrested that made Sultan spring back at him to come to their home.
Had he given him a chance to talk and perhaps helped him say lets see if we are really brothers with the DNA that's what Madhu wanted him to do to resolve the issue, but RK here though he regrets quarrelling with her so soon after marriage and hurting her, he still doesn't believe Sultan's story, he thinks Sultan is after Madhu. So it would not have occurred to him under those circumstances to talk to him or give his story a chance at all. But Madhu met him half way by saying even she doesn't know why Sultan is doing all this but they would resolve the issue together and that he must not hide from her anything that he has promised to do. So if Madhu is helping Sultan, her friend, to gather more proof, she will do it with RK's knowledge. I still think however if Radhaji tells her the truth, she must ask RK and Sultan to do the DNA test, that's the quickest way to resolve the issue and Radhaji doesn't need to reveal she knew anything about Meera and Mohan.