Two films released in the past month have raised the question of who exactly gets to call themselves a director, when multiple people have been instrumental in bringing a film to life - or to its death, as the case may be.

As we know by the existence of Alan Smithee - the alias used by directors who want to disown a movie - directors don't always get the final say over what appears on our screens. Alan Smithee isn't a casually deployed ego trip; the name is only allowed to appear on a film after a director has argued to a panel from the Directors Guild Of America (DGA) that he or she had not been able to exercise creative control, and they have found this to be true.

This loss of control can happen for many reasons, most commonly overzealous interference by producers or a studio. But distribution and censorship issues can also cause a director to remove his name from a film; for example, Martin Brest refused to lend his name to the altered version of Scent Of A Woman shown on airline entertainment systems.

But sometimes the problem is not that a director wants to remove their name from a film, but that an extra director also wants credit - and here, the issue gets thorny. Animated films have a long history of joint directing credits, due to the amount of technical work to be overseen and the lengthy production time. But when it comes to live action, the DGA is loath to give joint credit to directors who aren't recognised as a directing team who've shared a vision for the film from conception, such as Joel and Ethan Coen, Joe and Anthony Russo, or Lana and Lilly Wachowski.

This becomes complicated when a director of a live-action film leaves or is removed from a film during production, or when another director is brought in to complete reshoots or post-production. Such was the case with two films released in the past month: Bohemian Rhapsody and The Nutcracker And The Four Realms.

While Lasse Hallstrom directed the principal photography of The Nutcracker, he was unavailable for a month's worth of reshoots during post-production. This additional photography included a lot of intricate visual effects work, so effects-artist-turned-director Joe Johnston stepped in to shoot the new footage. Given that the visual effects of the plot-light and style-heavy film turned out to be integral, Hallstrom offered to share a co-credit with Johnston - a relatively rare arrangement, which probably would not have been enforced by the DGA had Hallstrom not been feeling quite so generous.

This point was proven by the release of another film this month - the now infamously troubled Freddie Mercury biopic, Bohemian Rhapsody. Even before shooting had begun, the chairman and vice-chairman of Fox sat down with director Bryan Singer to warn him that previous habits of being late, missing days and handing over reigns to cinematographers would not be tolerated. But all this happened - and more, as Singer had fights with star Rami Malek; caused actor Tom Hollander to temporarily quit the film; threw a piece of electrical equipment; and went AWOL in the final weeks of principal photography.

Singer later claimed he needed to care for his sick mother. Fox hired Dexter Fletcher to shoot the final couple of weeks - he completed principal photography and saw the film through its post-production. But despite Fletcher saving a film that was about to fall apart, he was not thanked with a director's credit. Singer's name is still on the film, though he was stripped of his producer's title.

Even after the Singer debacle, there doesn't seem to be any push for the DGA to change its standards. Perhaps it would be wise to look at the philosophy embraced by the team behind the 2009 animated film, Cloudy With A Chance Of Meatballs, who used the opening frames to recognise that no director is an island. Its credits read, simply, "A Film By A Lot Of People".