The speculations got more intense when Buffet admitted to making some "dumb decisions" and showered praises on Jain again - though no one knows whether the 22-year veteran at Berkshire will get the coveted seat.
So what is it in Jain that attracted the attention of the legendary investor? The answer is simple: He prevents "foolish losses" through his extraordinary discipline. And that's the key: Buffett believes insurers produce outstanding long-term results primarily by avoiding dumb decisions, rather than by making brilliant ones.
Jain was born in 1951, in Orissa. He graduated from IIT Kharagpur in 1972 with a bachelor's degree in mechanical engineering. After working in IBM, India between 1973 and 1976, he moved to the US, where he did MBA from Harvard and joined Mckinsey & Co.
He returned to India in the early eighties to get married. According to Robert P Miles' The Warren Buffett CEO: Secrets from the Berkshire Hathaway Managers, Jain confessed to his friends he would not have returned to the US, but for his wife who wanted to move there.
Jain specialises in mega-catastrophe coverage, that is, he takes risks that rivals avoid. For instance, he insured the Sears Tower in Chicago, America's tallest building, after the September 11, 2001 terrorist attack. He also underwrote the Winter Olympics at Salt Lake City in 2002, when big groups shunned the games as too risky after the attack.
A Bloomberg report in 2006 said that after joining Berkshire, Jain placed advertisements in industry publications, which read something like: "We are looking for more - more casualty risks where the premium exceeds $1 million. The Berkshire Hathaway Insurance Group currently has $2 billion in surplus - that's right, $2 billion. And, because we retain the entire risk ourselves, instead of laying it off in the uncertain world of reinsurers, we have the flexibility to respond to your specific needs."
This was typical of Buffett's style of building Berkshire by saying: "Send us your deals", and then just answering the phone.
In the last few years, there has been a lot of speculation about Buffett's succession. In dealing with it, Jain has shown that apart from his "extraordinary talent and discipline", he also shares with his boss an extraordinary sense of humour.
Sample this: In an email response to a reporter who wanted to interview him on Berkshire's succession, Jain wrote: "It is undoubtedly the case that any disappointment I have caused you by declining the interview is far less than the disappointment I would have caused you by granting it."
Meanwhile, the speculations continue.