I shared with the management team that deleting offensive comments is not only correct but acceptable if the rules of engagement were established upfront.
This is where the organization needed to establish an Acceptable Use Policy (AUP) governing the management of postings on the organization's wall. Once the AUP has been established, any breaches of these rules will then give the organization the prerogative to delete the post. The only suggestion I have for the organization is not to complete delete the offending post, but to replace it with a statement saying that "a post by <user> was deleted as it had breached the rules established in the AUP." This statement is important as it will then limit accusations of censorship.