The filmmaker Paul Watson had come under fire for inferring the last scene showed the moment Malcolm Pointon, once a talented musician, died of Alzheimer's. In this broadcast, Watson said he died three days after the last scene, lying incapacitated in a bed, skin and bones, unable to swallow and unaware of his surroundings.

Malcolm was diagnosed when he was 51, he died aged 66 and the flyon-the-wall documentary was 11 years in the making.

This was a labour of love for Barbara, who tended to her husband's every need even when he was violent. She said, "You can't do this job unless you love, really love, the person you're caring for." Her love was abundantly, painfully clear. It was a labour of something else for Watson. It has to be. A filmmaker brings a cold eye . . . for balance and to avoid cheapening the work with sentimentality . . . and, one hopes, a warm, true heart.

The controversy was unfortunate. Did they want that kind of publicity? Probably not.

Would as many people have watched it without the scandal?

Again, probably not. As a filmmaker, Watson knows it is more dramatic to show the moment of death, so he may have fudged it in the preview for journalists. Fortunately, it was made clear by the time of its broadcast. The head of ITV Michael Grade has ordered an investigation.

But Watson's voiceover was unwelcome, as when he said a lost Malcolm was "as a child frantically searches for his mother". And, when Barbara finally decided to temporarily put Malcolm in a home for respite, Watson's comment . . . "It's a sad day for us all" . . . was inappropriate. He is not part of the drama. Barbara and Malcolm agreed to the film, and, yet, how much would Malcolm have known about what would be broadcast?

Him, sitting on the toilet, his underpants around his ankles, a skeletal figure in bed . . . and all the gruelling scenes in between. At first, Barbara hid the diagnosis from him. She kept a book on Alzheimer's in a filing cabinet.

Malcolm . . . inevitably . . . found it.

"He was sitting under one of the apple trees in the garden, weeping uncontrollably, " she recalls. In a diary entry, Malcolm writes of a "silent physical buzzing in my head".

Watson used music by Malcolm, which was a poignant reminder of the man's previous life. His physical and mental descent into Alzheimer's was frightening and excruciating. Death and dying is as natural as birth, as any medical professional will flatly tell you, but there is little dignity dying of this disease. But, as a viewer, I also wanted to protect him from the naked voyeurism of television.

During the ads, UTV screened a montage for its summer schedule, including The Queen, X Factor and flashes of a smiling Malcolm too.

And that's in addition to the multiple ad breaks. Still, the crux of the public-interest issue is that heart disease is the number-one killer in the UK, dementia is number two, while cancer is number three, yet dementia too often gets sidelined.

Barbara wanted to highlight this. But was the companionship and validation of the camera partly a crutch for her throughout this ordeal, particularly when she lists her husband's violent moments? I don't mean that as a judgment. God knows, she needed it. But, as she refused NHS home help for as long as humanly possible, was this a way of holding onto her sanity? At one point, she said, "He's locked, locked inside himself, " and asked for a break from filming. Watson (off camera) said, "Can I just ask you one more question?" Even squeezing 11 years into under 90 minutes, the filmmaker will always have one last question. When was she ready to let go? Until there were no more glimpses of Malcolm left, Barbara said, she wasn't ready for him to die.

This was a brave film showing the cruel, brutal reality of dementia. But, controversy aside, it was the limited format of commercial television . . . with a battling filmmaker and television executives, who have their own interests, financial concerns and fiduciary duties . . . that combined to become the single, most unreliable narrator of all.

Reviewed Malcolm & Barbara: Love's Farewell ITV1