I would guess the reporter wrote down the numeral “2” in his notes and mistook it for the numeral “7” when he went to type up the story later.
Quite possible.
Reporter under deadline screws up. It happens in some detail in almost every story, at least the ones I've been involved with.
That is why we must rely on contemporaneous source documents and full transparency.
We must not rely on reporters, hearsay, foggy memories of senior citizens, partisans with a bias or ghost writers of self-promoting biographies.
The article was written in June 1962. The usual date for his arrival is summer 1959. He said he only had enough money for 3 semesters and would have to get a job to support himself. How could he afford to and why would he have gone to Kenya in 1960 if he had said 2 years? My research into the writer of the article leads me to believe he was very smart and careful about what he wrote. He also probably wrote the article very soon after the interview and since two sounds nothing like seven I don’t think it was likely he would have confused the two or forgotten what 0 Sr. actually said. It’s possible he could have made a mistake but considering how busy 0 was with completing 2 degrees in 3 years with top honors, working at a job, socializing with his “friends” and possibly marrying a pregnant white teenage girl and whatever else he was doing, he had no time to be taking off to visit Kenya.