"Close" Osama Associate Surrenders

CNN has this as breaking news:

Close associate of Osama bin Laden, Khaled al-Harbi, surrenders to Saudi security officials in Tehran, Saudi official says.

Something about this rings a bit hollow.

I remember reading small bits about this man, but nothing to imply (that I recall) he was like this with Osama. But whether his status is being exaggerated now, I cannot say.

However, why surrender, and why surrender in Tehran?