Joseph: It is clear to anyone who sees the Beis Yosef that the case in question is one where there is an ongoing feud. No one can be Mochel the other and this feud clearly became public. Therefore, if one person wants to end the feud but the other doesn’t, the person who wants the feud over should public declare that he is Mochel and removing himself from the situation. Then the onus is now on the other person to end things.
The Shulchan Aruch does not mean that if someone wronged someone privately that they have any right to publicly declare that the other refuses to forgive him. If you read it Kipshuto, you might think that, but then your punishment for not properly learning and understanding the Shulchan Aruch is that you end up being Malbim Panim B’Rabim.
Avram: That applies whether in place of work or home or anywhere else. Publicizing someone’s unwillingness or inability to forgive when it was not otherwise known is violating many Issurei D’Oraisa.
And Joseph, Avram was correct. A proper asking of Mechila requires giving the wronged person enough time to “get over” it. Rosh Hashana doesn’t magically mean that the person has moved past the issue. Maybe he should have waited until the next Rosh Hashana if 8 months wasn’t enough.