Despite the general rule of admissibility, it is frequently held that evidence of a party's silence cannot be introduced as proof of an admission unless the following conditions are shown to have existed: (1) the statement in question was made in the party's presence and hearing, (2) the party was capable of understanding the meaning of the statement, (3) the party had sufficient knowledge of the facts embraced in the statement to reply thereto, (4) the party was at liberty to deny the statement or otherwise respond to it (5) the statement was made under such circumstances as would naturally call for a reply, and (6) the statement was made by a person normally entitled to a reply. In other words, there must be a specific showing that the silent party adopted the statement by failing to refute it.
After all, no one is required to respond to every negative or joking comment that is made about him. And there may be other factors in a given situation, apart from guilt or innocence with respect to the particular accusation, that might explain why a person did not choose to respond.
On the other hand, some accusations may be of such a nature, or come from such a source, that it may be natural to expect an innocent person to protest when such an accusation is made to his face if there are no other explanations for his silence.
Compare: Admission by Silence occurred during Clinton’s press conference : a reporter asked the President two important questions with such clarity that no wiggle room was left. "Is Monica Lewinsky's account to the events accurate and truthful? Did you lie?" Bill Clinton did not answer either question