ABOUT halfway through our conversation John Michael McDonagh tells me about the moment on his latest movie The Forgiven, filmed in the desert in Morocco, when he could have died.

“A driver was speeding me from one location to another into the sand dunes,” the film director begins. “I don’t know why he was speeding because we were on time.

“And he flipped the car. Larry Smith the DP [director of photography] is in the car with me and Larry, for reasons unknown, didn’t put his seatbelt on.

“So, he’s flipped the car. I’ve got Larry on top of me and I’m trying to get out of the car hoping it’s not going to fall on me.”

McDonagh pauses, enjoying telling the story. Because why wouldn’t he? Telling stories is his job after all.

“We got out,” he concludes. “What was great about that was I’d already built up a list of people I wanted to fire on the crew and I was like, ‘I need a good reason.’ And I thought, ‘Well they’ve almost killed me … That’s a pretty good reason to start firing people.’”

I think this story serves not only as a warning of the dangers of shooting in the desert but also offers a snapshot of McDonagh himself. As an interviewee he takes no prisoners.

Thursday afternoon, the day after the night before. McDonagh, the London-Irish director of The Guard and Calvary, both of which starred Brendan Gleeson, and more recently War on Everyone, is in the Scottish capital for the Edinburgh International Film Festival. The Forgiven had its UK premiere at the festival last night. “It was fine but it wasn’t full,” McDonagh laments.

The film, adapted from Lawrence Osborne’s novel of the same name, stars Ralph Fiennes and Jessica Chastain, with an impressive supporting cast that includes Matt Smith and Moroccan actors Ismael Kanater, Said Taghmaoui and Mourad Zaoui.

It’s a film about rich people; rich, careless, indifferent people. It’s also a film about guilt, atonement and how good Chastain looks in Ralph Lauren.

The result is a lush, visually thrilling movie. But it’s the story and the characters that people have been reacting to. To be frank, McDonagh seems more than a little exasperated by the reaction to the film in the United States. Fiennes and Chastain play a couple whose marriage is in trouble. On the road to a party in the desert their car strikes and kills a young Moroccan. The film then traces the consequences for both of them, their friends and the family of the dead young man.

“I’ve seen the film described as a satire,” McDonagh says. “It’s not a satire. Satire, as far as I understand it, is you’re trying to make a political point. I’m not trying to make a political point. I mean what’s the political point? Rich people can behave like scumbags? I don’t think that’s a new idea.”

For what it’s worth, I think the film is a pretty gripping noirish story about people you might not like. Yet some of the film’s critics even seem to have taken particular umbrage to the mostly moneyed indifference of the film’s European and American characters (without which there wouldn’t be a movie).

“Yeah, that American idea of ‘I need someone to root for,’” McDonagh suggests when I bring this up. “Why? I don’t need someone to root for when I’m watching a film. Why would you need that? But a lot of the reviews you read, the negative ones, they don’t like unsympathetic characters. That has kind of surprised me. That reaction.

“To me, if a film is interesting it has a good plot, and you like the actors. You don’t have to like the characters. The actors are absorbing you in the film. This idea that you immediately have a negative reaction to a film because the characters are sort of negative … I find it really strange.

“It never used to be that way in the 1970s. But we’re a long way from that now, I guess.”

More importantly he points out, The Forgiven is not a film just about rich westerners. “The Moroccan characters were proper characters in their own right. When we see films from that part of the world it’s usually American soldiers shooting them and them feeling sad about it later. That’s the only way we see them on film these days. Or they’re the quirky best friend, something like that.

“So it was good to have fully rounded characters who have reasons for what they are doing.”

Part of the appeal for making the movie was shooting in Morocco, McDonagh says. He likes going on location.

There is the odd downside, though. Near death incidents for one. Any others? “Well I should have cut down on my boozing while I was there because I got severe dehydration so I was shitting water for three days. It helps you lose some weight. But not in the best way.”

Growing up, John Michael McDonagh wanted to be a novelist rather than a film director. “I’d written five or six bad books that never got published and so I was trying to figure out what else I can do where I don’t have to get up early in the morning and say yes sir to anybody.”

He decided to write screenplays. And people were interested immediately. McDonagh sold a script about Australian outlaw Ned Kelly which was made into a movie starring Heath Ledger. But he was not happy with the result.

“If I hadn’t had a bad experience with Ned Kelly I probably would have continued to be a jobbing screenwriter. I didn’t really have an ambition to direct. It was just that the film didn’t turn out the way I wanted and the director was an idiot. I thought, ‘Well, if it is people like this who are in charge I will retain control of the script and do it myself.’

“I got paid quite a lot of money for writing Ned Kelly and I wasted a lot of years travelling and enjoying myself. And as the money ran out I thought I better start writing again.

“There were various projects I was trying to get made and for one reason or another I couldn’t get them financed and basically I ended up in such a negative, pissed-off place that I created the Gerry Boyle character in The Guard. And that one immediately got up and running. But at the same time I’m saying, ‘I’m not having someone else direct this. I’m not going through that again, so if you want the script I have to be the director.’”

It worked out rather well. Although not as high-profile a film-maker as his younger brother Martin (director of In Bruges and Three Billboards Outside Ebbing, Missouri), he has continued to make films on his own terms. But it’s never easy being an indie film-maker. Is television another option? He has projects in development with HBO, he says. “So I’m not opposed to it. I do find, though, that this whole golden age of TV is just a load of bullshit. If you look back on a year and you think of how many TV shows are really good, right? Maybe you’d come up with three, four. You’ve got to have really low standards for that to constitute a golden age.

“I can barely get through a show. I’ve found they’re nearly all padded. I find it quite frustrating watching them.”

Let’s get back to guilt and atonement. Both The Guard and War on Everyone dealt with police corruption. Calvary was about goodness and retribution in an institution (the Catholic Church) that was seen as morally compromised. Given how often ethical dilemmas crop up in his work, the question I really want to ask him, I say, is does he think he’s a moral film maker?

“Am I moral? No, I don’t really judge films in that way. To me that’s what the critics are there for they’re there to tease out all the complexities and ambiguities and thematic concerns.”

And yet those themes recur time and again in the work. Actually, I wonder if his work is not just moral but religious?

“I used to be an altar boy. Catholic guilt is great. All the religious symbolism. The story of Jesus Christ is a pretty great story. I obviously absorbed all that as a kid and it’s nice to play around with all that; the idea of redemption and everything. It’s just an interesting sort of arc for a character … It can become a cliche as well.

“But I’m not a religious person. I look back on Calvary and I wonder where that came from because that came fully formed. I was expecting there to be loads of movies about evil priests so I thought I’ll write a film about a good priest.”

One day he hopes to complete the trilogy he started with The Guard and Calvary. The script is ready and waiting, but for now his next film will be a chase thriller set in the Australian outback, which he hopes to shoot next year.

Another desert movie? “Yeah, in another hot location. I’ll watch my booze intake this time.”

The Forgiven is in cinemas now