Who are these others? One explanation is that a murderer whose verdict has not been finalized - even though the judges have voted for a guilty sentence - got mixed with other murderers whose verdicts have been finalized. Since the verdict has to be announced in his presence, and they don't know who he is, and since moreover, they have to say to him, "So-and-so, you are liable," and again, they can't - he is free and with him all the other murderers. Rabbi Yehudah holds that since, after all, they are murderers and cannot be executed only because of a technicality, the court causes their deaths indirectly.
Art: A Wine Cellar by Johann Sperl