The only time I do not use the official score card is if its raining constantly and you score on a local card to preserve the condition of the card you will be submitting. Then once the scores are transfered at the end of the round IN THE CLUB HOUSE you double check the hole by hole score, your name, hcp, date before signing and always, always submit your card yourself.
Had an instance a few years back where one person was to hand in all four cards. Went into club house, went to bathroom and on coming out got into a conversation with an old buddy and totally forgot the cars were still in his back pocket until he got back to his motel room. OOPS. He sincerely apologized for the next two days but the fact remained that the entire group was DQ