Nearly five months ago, I sat in the delegate room at the Cannes festival center waiting for Lars von Trier to arrive for his press conference, fully expecting some of the senior enfant terrible's requisite fun-and-games (or foot-in-mouth, depending on your take). The director has, of course, made something of a professional trademark out of his contentious public statements -- and duly delivered on this occasion.

As if to compensate for the fact that his thoughtful new film, "Melancholia," is among his least overtly provocative to date, a jovial Von Trier followed it up with the most playfully sensational press conference of his career. You've heard the rest, though quite possibly not in the right context: "I am a Nazi" are unwise words to utter under any circumstances, but as they filtered through the media's echo chamber, they were swiftly stripped of the unambiguously ironic tone with which he said them, as well as the fact that they were in response to a journalist's unprompted (if wholly reasonable) question about the possible influence of a Nazi aesthetic on his work.

YouTube could easily clarify this situation for anyone willing to check, but predictably, not that many were. Soon, the quip had become the legend -- Lars von Trier is an out-and-proud Nazi! It was an unhappy outcome for an inelegant joke for which the phrase "you had to be there" might have been invented. And that was before Cannes festival brass decided to raise Von Trier's stupidity with more of their own by dimly taking his comments at face value and melodramatically "banning" him from the festival.

I wrote at length on this silly farrago at the time, and was rather hoping I wouldn't have to do so again. For one thing, with the dust settled, it seemed as if the Cannes festival organizers' tantrum had worked inadvertently in Von Trier's favor.

His leading lady Kirsten Dunst, who winced with the rest of us through the press conference, was rewarded days later with the Best Actress prize, while the film, riding a wave of publicity that had nothing to do with its content, has proved an arthouse hit: the French flocked to it, while last week, it scored the highest opening-weekend gross of any of the director's films in the UK. The director, meanwhile, has been lucid and graciously sheepish in several subsequent interviews: Lars, it would appear, always lands on his feet.

Or perhaps not. The latest twist in what should be a thoroughly cremated horse of a story is that French law has apparently intervened, accusing Von Trier of illegally justifying war crimes -- a conclusion so far from the original events of that fateful press conference as to approach Monty Python levels of absurdity. The director, however, is sufficiently shaken by this development to respond with what must, for him, be the hardest course of action: keeping his mouth shut. You may already have read the statement he issued today:

"Today at 2pm I was questioned by the Police of North Zealand in connection with charges made by the prosecution of Grasse in France from August 2011 regarding a possible violation of prohibition in French law against justification of war crimes. The investigation covers comments made during the press conference in Cannes in May 2011. Due to these serious accusations I have realized that I do not possess the skills to express myself unequivocally and I have therefore decided from this day forth to refrain from all public statements and interviews."

Whether Von Trier intends to uphold this commitment or not is entirely open to question: less arguable is that the man certainly knows how to make productive theater of his career speed-bumps. The question, however, is immaterial to the unsettling implications of the charges levelled at him: aside from being ludicrously shy of the truth, they allow scant room for freedom of speech. Even taken literally, Von Trier's words were non-aggressive statements of belief, relating to his own art; the closest they remotely came to hate speech was a barbed but amusing dig at his filmmaking compatriot Susanne Bier.

This will only stir up more of the same media back-and-forth about the relative social responsibilities of artists, even potentially insane ones. The film, meanwhile, will continue to benefit even as it sinks into the background of its own conversation; poor Kirsten Dunst, on the other hand, will continue to have the varnish stripped off her career breakthrough by having to discuss this nonsense with every journalist she encounters. So far, so old. But if Von Trier is serious about this, and the final consequence of this empty controversy is that one of the world's most exciting filmmakers will no longer be willing to discuss his own work for our benefit, then nobody's really winning.