Are you aware that the timeline of the gospels is about 30AD or so? The author is implying that stoning ended in Judea sometime between the AD 30s and 79AD when the (Second) Jewish Temple was destroyed. As a historical note, the Romans didn't typically let capital punishment be carried out by local authoritie. Capital crimes under Roman law which were carried out by Roman authorities.
Regarding your comment:
All nice and well. But this doesn't solve the contradiction in the author's article.
The "before that" is open to interpretation, either meaning what you suggest, or what I read into it. He doesn't specifiy at all what you are saying. Regardless of that, the fact that during Jesus lifetime, Jews were trying to stone a woman for adultering, was certainly no exception and refutes the author's assertion that the practice of stoning has no relation to Judaism.
The only thing wrong with the quote from the makers of the film, is tying stoning to Christianity.