Dying declarations are accepted in court when testified to by witnesses. Rabbi Akiva was being combed with burning rakes by the Romans when he said he had said the Shema every day, repeating the commandment. Under torture unto death, he rejoiced that he now
knew that he had kept it.
Of course, someone who understands it as an actual commandment to be obeyed will probably be better at it than someone who understands it as some sort of trick question.