In an interview with The Associated Press on Friday, Ellis, the pastor of the 6,000-member Greater Grace Temple in Detroit, apologised.
"I personally and sincerely apologise to Ariana and to her fans and to the whole Hispanic community," Ellis said. "When you're doing a program for nine hours you try to keep it lively, you try to insert some jokes here and there."
He told the AP that any inappropriate touch was incidental, and that he had hugged all the performers, male and female. Hugging, he said, is a common way of showing love at his church.
"It would never be my intention to touch any woman's breast. . . . I don't know I guess I put my arm around her," Ellis said, adding: "Maybe I crossed the border, maybe I was too friendly or familiar but again, I apologise."
But for many the apology was not enough. They held up the touching as a public display of what routinely happens to female artists in an era of #MeToo.
"THIS IS SO DISGUSTING AND DISRESPECTFUL," one person said on Twitter.
And many said the affront was not the only one Grande endured during her brief time onstage.
Fox News panelists, for example, blasted former president Bill Clinton for apparently staring at Grande's backside during her performance as the singer performed directly in front of him.
Some on social media dragged the singer for wearing a short black dress to a funeral, which some deemed disrespectful.
Publicly, Grande has been quiet on the matter. She could not immediately be reached for comment on Saturday.
But her defenders responded with tweets that included the hashtag #RespectAriana.