That is quite an unetical move by Harvard, they are the ones that made the information public, and then punished those who viewed it.
The HBS folks incorrectly thought that their work in the system was private.
TBH, they should be mad at the company and mad at themselves for not engaging in due diligence. That said, I can see how this would be an ethical violation, akin to asking a friend who works in the admissions department for an update.