But when Guru-Murthy asked questions about his long-conquered personal demons, the star could be seen getting visibly uncomfortable.
Specifically, the news anchor asked Downey Jr to explain a comment in a five year-old interview with The New York Times, in which he said: "You can't go from a $2000-a-night suite at La Mirage to a penitentiary and really understand it and come out a liberal."
Responding, Downey Jr said: "I could pick that apart for two hours and be no closer to the truth than giving you some half-arsed answer right now. I couldn't even tell you what a liberal is," he added.
But, when asked about his relationship with his father, Downey Jr says: "I'm sorry, I really don't ... what are we doing?" before saying goodbye and walking out of the interview.
Seemingly amused with the reaction, Guru-Murthy can be seen smiling and gesticulating as a production team-member tried to remove Downey Jr's clip-on microphone.
At that point he turns and says: "It's all getting a bit Diane Sawyer [who is known for her touchy-feely investigate interviewing]."
Clearly wanting to keep a dignified silence on the matter, the veteran star - who originates from Manhattan and has battled both drug addiction and prison - resisted the temptation to make reference to the incident on Twitter.
Unlike him, however, Krishnan twice shared details - captioning one video: "A steely moment from Ironman."
But viewers weren't impressed, with nearly three-hundred "disliking" it within hours.
Tellingly, the comments which followed shared a similar opinion.
One wrote: "God, Krish you can be an a**. When your interviewee is uncomfortable, don't keep pressing them. Props to RDJ for ending it."
Another simply said: "No class at all."
- Daily Mail