Though at the time his sister was obviously caught off guard by Larry King's knowledge of the situation and related line of questioning ( watch the video here), Donny Osmond now says the CNN talk host did Marie a favor by bringing up her 16-year-old son's enrollment in rehab. "I have to back up and apologize publicly to Larry King," Donny said Monday on Today, referring to some harsh words he lobbed at King in the immediate aftermath of the emotional sit-down. "In hindsight, [he] did Marie a favor. She was able to make a statement about the situation [before the tabloids grabbed hold of the story]. And so she's grateful to Larry."