Washington, D.C. — Republican presidential candidate Herman Cain said on Sunday that he regrets not defending a gay soldier whose videotaped comments were booed during a Tea Party-sponsored debate last month.

"In retrospect, because of the controversy it has created and because of the different interpretations that it could have had, yes, that probably -- that would have been appropriate," Cain said on ABC's "This Week."

The soldier, Steven Hill, had joined the debate from Iraq and asked this question: Hill: "In 2010 when I was deployed to Iraq, I had to lie about who I was, because I am a gay soldier. I didn't want to lose my job. My question is, under one of your presidencies, do you intend to circumvent the progress for gay and lesbian soldiers?"

That's when the audience booed.

Candidate Rick Santorum had responded: "I would say that any type of sexual activity has absolutely no place in the military."

Santorum's comments were met with cheers.

Cain said he wasn't sure right away why the audience was booing.

"I happen to think that maybe they were booing the whole 'don't ask, don't tell' repeal more so than booing that soldier," he said.