Hmm, I just saw or read this same scenario, except that the jury finds the defendant guilty after being convinced by the one juror who had the presence of mind to keep his eyes on the defendant, who didn't bother to look back toward the door. The way I saw/read it, the defense attorney (and I, as the viewer/reader) learns this when he interviews the juror in question, post-verdict.
Thanks a bunch, jdc. Now this is going to drive me crazy. Just out of curiosity, what was the Korean film?