Bull got off to an incredibly strong start when it first premiered on CBS in 2016 as a new series to showcase Michael Weatherly, who had departed NCIS the previous TV season. The show and its star started making headlines for some unfortunate reasons in late 2018 when Weatherly was accused of sexual harassment by former co-star Eliza Dushku.
The controversy didn't stop CBS from renewing Bull for a fourth season, however, and CBS entertainment president Kelly Kahl explained why:
Michael made a mistake. He owned that mistake… he was apologetic at the time; he was remorseful… [Michael made himself open to] whatever coaching or training is necessary to create a positive environment on set. He took everything very seriously and wanted to move forward.
According to CBS entertainment president Kelly Kahl, it was enough that Michael Weatherly regretted the behavior that upset Eliza Dushku and acknowledged he had made a mistake. Kahl seemingly did not clarify whether or not Weatherly did receive any coaching or training to create a positive environment on the Bull set, but he was apparently open to it. Of course, it's not surprising that he would want to move forward. Bull may not be an NCIS or Big Bang Theory for CBS, but it's still a primetime broadcast network TV hit.
The controversy surrounding the show and Michael Weatherly started back in December 2018. Eliza Dushku claimed that Weatherly's behavior on set made her uncomfortable, with alleged comments ranging from jokes about spanking her, jokes about having threesomes, and joking about taking her to his "rape van" on set. For his part, Weatherly said that he was sorry and did "regret the pain this caused Eliza."
Eliza Dushku stated that she was written off the show after making complaints about Michael Weatherly's behavior, which put an end to what had been intended as an arc as a series regular character, and CBS settled with Dushku with a sum that "reflects the projected amount that Ms. Dushku would have received for the balance of her contract as a series regular," and it was mutually agreed upon. For their part, a couple of Weatherly's former NCIS co-stars defended him.
Kelly Kahl went on in his chat with TVLine to say why CBS made the ultimate decision to bring back Bull:
When we looked at the totality of the situation, we felt comfortable bringing it back on the air.
CBS may have felt comfortable bringing Bull back in the 2019-2020 TV season, but executive producer Steven Spielberg and his Amblin TV company pulled out of production. Although nobody from Amblin commented on the decision after the news broke, the announcement came in the wake of Bull's renewal despite the controversy. Spielberg was a supporter of the Time's Up movement, and he reportedly met with Eliza Dushku before making the ultimate decision to leave Bull.