I have to admit that I didn’t check the wording in our alumni magazine, Columbia College Today when they ran the article on Obama.
I was surprised to see it because I had already seen all the questions about his Columbia provenance but just assumed it was verified just by the fact of the article which claimed him as a Columbia student.
Columbia College Today might have written the piece, as you suggested earlier, simply to claim a presidential connection.
But being of a narrow eye, I suspect that Obama’s narrative managers midwifed the story so other media players could plausibly “misinterpret” alumnus to mean graduate, thus anchoring false conventional wisdom without the risk of being caught lying. It is a shame that the world has come to this. [The Democrats used the work of Jonathan Gruber to give the ACA theoretical legitimacy in a very similar game of round-the-rosie].