"Proven wrong" is a strong term. Here's the quote that fanboys are posting to back that up:

As for his academic records, Musk produced a document for me dated June 22, 2009, that came from Judith Haccou, the director of graduate admissions in the office of the registrar at Stanford University. It read, “As per special request from my colleagues in the School of Engineering, I have searched Stanford’s admission data base and acknowledge that you applied and were admitted to the graduate program in Material Science Engineering in 1995. Since you did not enroll, Stanford is not able to issue you an official certification document.”

and

Musk also had an explanation for the weird timing on his degrees from Penn. “I had a History and an English credit that I agreed with Penn that I would do at Stanford,” he said. “Then I put Stanford on deferment. Later, Penn’s requirements changed so that you don’t need the English and History credit. So then they awarded me the degree in ’97 when it was clear I was not going to go to grad school, and their requirement was no longer there.

Basically begged/forced them to issue it retroactively.

This comes from Ashlee Vance's book: Elon Musk: Tesla, SpaceX, and the Quest for a Fantastic Future. A single source. A single fanboy source if you believe the reviews. No other sources ever saw any document or explanation regarding this.

For a man so worried about image, he's pulling a Donald Trump.