In the April 10 issue of TV Guide, NBC's Behind the Camera: The Unauthorized Story of Mork & Mindy — airing tonight at 9 pm/ET — gets Jeered for "reducing Robin Williams to a perky yet sad clown." Ouch! Natch, the film's leading man denies his portrayal is just a gratuitous rehash of Williams' alleged setside diva behavior and drug problems.

"I don't think the movie's exploitative," Chris Diamantopoulos tells "By nature, a biopic — whether the person's alive or dead — is [for] making money. Even Ray, to some degree, is exploitative.

"A lot of people ask how I think Robin Williams feels [about this film]," adds the 29-year-old thesp, who's guest-starred on everything from American Dreams to Nip/Tuck. "How would you feel? A movie's being made about you and they're not asking for your advice, opinion or permission. So even if the movie comes out a masterpiece, it's still gotta be frustrating. It's OK for him to joke about his [past], but when it's put on the screen as a drama, that's gotta be unnerving. He probably feels the way anyone would feel.

"I can only hope someone close to Robin Williams will watch and realize — without sounding cheesy — that what we've ultimately done is venerate him. He went through such adversity and came out a clean hero on the other side."

That said, Williams may still hate it. Does Diamantopoulos look forward to a punch in the nose if he should ever encounter the former Mork From Ork in the flesh? "He's a classy gentleman. If he were to come up to me and say 'F--- you,' I'd have to take it, but I can't imagine that would happen.

"The one really big advantage that I have is that I look so little like what I play in the movie that I can disassociate myself from it," he chuckles. "One reason I almost didn't get an [audition] appointment is that I look nothing like [Williams]. In the film, I'm wearing a wig and these prosthetic contact lenses that are handpainted to be almost retinal copies of Robin Williams's eyes."

To his credit, Diamantopoulos needed no cosmetic assistance to uncannily mimic the comic's speaking voice. (Seriously, it's eerie.) "Most of the actors passed on this because no one wants to go down in history as the guy who tried to be Robin Williams," he says, "but playing regular characters is boring for me. I'm sort of a vocal chameleon."