Sail fair! The person seeking advice on the forum is the protestee in the incident. In fact he/she doesn’t debate that he/she is in the wrong. Therefore my advice is sail fair: If you infringe somebody (and they shout protest, which you are debating, but not apealing) take a penalty.
If you know you are in the wrong and you end up in the PC room; plead guilty. Debating the validity of the protest in the PC room knowing you are in the wrong is not chique.
By considering an appeal for such a case, you’ve lost my respect. That is all.