Do you want to see every parent in the dock?

"Yes. Well, we send the teenagers to do the checking."

I wonder if he realises how fortunate he has been. If something terrible had happened, can you imagine the headlines? They would probably say something like: "Teenagers checked on missing toddler while parents partied."

I have written about the McCanns a number of times, most recently last week, since their daughter Madeleine went missing in May 2007. It is unusual to return to a subject two weeks in a row. I am doing so only because I am stunned by the level and degree of venom their story continues to excite.

Shortly after Madeleine disappeared, I put it down to emotional public over-reaction. Fourteen months later, I have run out of excuses. The want of compassion is shocking; the desire to punish the parents shaming. I am not in the business of exonerating anyone. The McCanns did leave their three children unattended for half an hour at a time while they and their friends had dinner. They followed the same pattern throughout their holiday. Their behaviour carried risks for the children, one of the worst of which was realised.

What I have tried to say is that the price this couple has paid exceeds their offence by an incalculable number of multiples. The suffering they have endured and continue to endure negates any necessity for reprimand. Does even their sternest judge imagine they are not their own greatest critics; that they aren't consumed by regret and remorse?

I criticised the Portuguese police last week after the country's attorney-general made a statement in which he said the McCanns were named as suspects in the absence of any evidence. According to some readers, my real motivation was to support middle-class doctors against working-class police officers. The McCanns put their pleasure before their children, said one. If they were blue-collar workers, the British police would have been waiting for them on the tarmac and falling over themselves to prosecute, said another. The McCanns should be prosecuted for neglect, goes the common cry. These people don't even mention the kidnapper.

I imagined the fact that Kate and Gerry McCann are doctors would stand them in some regard, since they spend their lives trying to help others. I was wrong. I thought the clear evidence from family photographs that Madeleine was a happy, well-cared-for child would demonstrate that leaving her unsupervised was an aberration, not the norm. But I didn't allow for jealousy and resentment.

So let's think about that call for prosecution. If the McCanns are to stand in the dock, who should stand beside them? We can start with those who were on the same holiday and who didn't hire a babysitter. Then what about all the other couples who have stayed at that or any family-friendly holiday village where they felt safe enough to leave the children unattended while they ate? What about people who eat in the garden on hot summer evenings while their children sleep in the house? What about parents who sleep indoors, maybe one night a year, while their kids sleep in a tent? If we apply these standards, the courts would be jam-packed. And that is my point. Childcare follows the same principle as travel: "He's a tripper, you're a tourist and I'm a traveller." Parents have a way of rationalising that what they do is safe; what someone else does is neglectful.

I know parents who pride themselves on their devotion but who would send their youngest to the park in the charge of their 12-year-old. I know parents who have hired 14-year-old girls as babysitters. I know others who thought it was character-forming to let their eight-year-old get the bus home from school. I wouldn't have done any of it, but I'm sure I did things those parents regarded as wrong.

When I look back at my own childhood, I'm amazed at the freedom I had. I walked to primary school, first with a big sister but very soon with friends. I played outside until supper. I was cycling for miles by the time I was 10 and was sent to Europe alone at 15. Times were different, I know. We children knew to avoid in the area. But what our parents must have relied on was an understanding of shared values in the neighbourhood. They knew everyone would look out for us. Isn't that what the McCanns thought they knew about Praia da Luz?

There is another sort of parent; the sort who guards their children morning, noon and night, and who polices their every action so the children either explode in rebellion or grow into cowed teenagers. Are they any better?

What I don't know is an honest parent who doesn't look back with some measure of regret. We are all amateurs when our first baby is born. As our families grow, we learn by our mistakes - for we all make mistakes. We are too strict or too lax. We push them or take too little interest. We get cross when we are tired and stressed. Then we walk into their bedrooms when they're asleep, looking so small and so innocent, and we are consumed by guilt and determine to do better tomorrow. It's a determination that lasts until 5am, when one of them prises open our eyelids and wants to play. We learn to live with our shortcomings for the simple reason that we also know, above all else, that we love our children.

Isn't that the bottom line? Do we want to see the courts filled with caring parents who made a mistake? Court is for the truly negligent and downright abusive. Too many children are starved of love and are physically, sexually or emotionally abused. They are the children of addicts, who get no attention, or of abusers, who get far too much of the wrong sort. We know that Madeleine McCann's parents slipped up. We know that if they had stayed in their holiday flat, taken the children out to dinner with them or even hired a babysitter, no kidnapper could have taken her at that time. We also know that Kate and Gerry McCann love Madeleine and her twin siblings. This was not a neglected child. Looking at what Madeleine's loss has done and is doing to her parents, no-one can imagine there is a sentence any court could hand down that would punish them for going out to dinner any more than they are already being punished.

So get off their backs.