Failure to sign pre-trial agreement

Dear PAO,

What is the possible effect if the pre-trial agreement was not signed by the accused? My nephew's friend is facing a criminal case. According to my nephew, his friend had no participation in the crime he was being accused of. So, during the pre-trial conference, he did not sign the agreement as it allegedly contained pieces of information that he said were neither true nor had happened. Recently, his friend learned that there was already a pre-trial order despite him not having signed the agreement. Although he is not certain if there is really an order, just in case there is, can that pre-trial agreement be used against my nephew's friend?