I was just thinking the same thing, I'm not sue there has ever been an explanation, assumed Sandro was under an NDA which he forgot about when doing the interview
I am pretty certain that this is exactly what happened in this scenario.
Sandro could well have got himself in a lot of legal issues over this if it came out publically that he was in breech of the NDA, via some form of legal proceedings etc.
The club, I am sure, were totally unaware of the interview hence why it was removed so quickly to save any possible embarressment for Sandro, and not because it contained anything detrimental for the club.
It was a sensible move by Sam to avoid any possible legal repercussions against Sandro alone and not that there was any pressure from the club on Sam to remove it.