Cherry took the stand in Sheridan's wrongful dismissal trial and faced the actress' attorney, who quizzed him about the incident which the star believes led to her firing from the show.
When he was asked how long he had felt awful about hitting Sheridan in the head, he said "going on three and a half years now". But he quickly justified his action, explaining he was merely demonstrating what he wanted for a particular scene.
Cherry explained he didn't ask Sheridan for permission to strike her, insisting: "I didn't think I needed to. Permission was understood."
Sheridan maintains Cherry hit her after she approached him with a rewrite idea for one of her scenes.
The actress claims she complained about the incident to ABC network executives, but no action was taken.
Shortly afterwards she was informed her character, Edie Britt, would be written out of the show.
Cherry told the court he opted to apologise to the actress, adding he was upset with himself for hitting a woman.
Sheridan completed her testimony earlier on Monday by tearing up as she read a letter from an ABC executive complimenting her on the way she was dealing with her final episodes on the show.
Cherry began his testimony by telling the court his decision to kill off Sheridan's character was a creative and cost-cutting choice, but he confessed Sheridan's "unprofessional behaviour" on the set was a factor.
He alleged the actress complained about her co-stars, forgot her lines and questioned him about the script.
Cherry also suggested Sheridan was often late for work, although he never actually witnessed this.
The writer/producer also claimed that Sheridan had been mean towards a crewmember.
The case continues.