Last Night's TV: The 9/11 Faker, Channel 4<br />Secret Diary Of A Call Girl, ITV2

Even now, when trick-or-treating and high-school proms are insinuating their way into British culture, the gulf between here and the US is vast, and every now and then it's worth being reminded of the fact. There were a couple of points in last night's The 9/11 Faker that brought home the difference.

Helen Littleboy's Cutting Edge film told the story of Tania Head, who for some reason – one of the film's many failings was its inability to even ask the question properly – took it into her head to pretend that she was a survivor of the 9/11 attacks on the Twin Towers. According to her story, she had been on the 78th floor of the South Tower when the second aircraft hit, and so was one of only 19 people who were above the point of impact to escape. She suffered terrible burns to one arm, and her fiancé (in some versions of her story, husband), who was working in the North Tower, died.

Over time, Head established herself not simply as a survivor, but as a kind of tragic star turn. What hadn't killed her had, apparently, made her stronger, just the way it's supposed to. She became furiously active on behalf of survivors of the attack (one woman said that Tania always made her feel guilty for doing so little), and when New York's mayor and governor visited Ground Zero for a ceremony, she was the person chosen to conduct them round and tell her story; and she ended up in charge of an organisation working for survivors. There seemed to be no question of Head having made any money out of this. It was even said here that she spent quite a lot of her own money helping survivors, though the claim went unsupported. And she did some real good. Her lobbying was instrumental in gaining for survivors the right to visit the site, previously open only to relatives of the dead. Eventually, though, questions were asked. New York Times reporters who had interviewed all the survivors above the impact point couldn't work out how her story fitted in. They poked around, and last year published the results of their investigation. Tania Head was actually a Spanish citizen, whose wealthy family had some years earlier been involved in a massive fraud case. On 11 September, she was attending business school in Barcelona.

That she could get away with her story for as long as she did didn't strike me as surprising in itself. As several people noted, even when it occurs to you that a story of suffering sounds phoney, you feel awkward asking questions. One fellow survivor, Gerry Bogacz, did go so far as to ask her for her fiancé's surname (she only ever referred to him as "Dave") and went on to check a list of the dead, but finding the name there, he didn't push any further. What was weird, though, and struck me as very American, was the tone of the stuff she said.

In a writing group established for survivors, she wrote that "Something gave me the strength to get out. I believe today it was my fiancé on his way to Heaven." At one point, the parents of Welles Crowther asked to meet her. Their son, identified by others as the "red-bandanna man", had died in the South Tower after helping a number of people to escape, including, so she said, Head. She said he had beaten out the flames that had left her so burned. At lunch, she told them that she kept photographs of Welles all round her apartment so that she could feel his presence, and promised to have a fragment of the clothes she was wearing that day preserved in a block of Lucite, which she would present to them as a kind of shrine. You simply couldn't get away with that sort of emotional excess in this country. It would be seen as tasteless or a sign of mental imbalance. Wouldn't it?

Mr Crowther thought that Head had lied because of self-esteem issues, related to the fact that – "Don't tap me on the leg, dear," he told his wife, "I'm going with this" – she was fat and not attractive. Whether or not that was fair, to Head or fat people generally, in the context it came across as a kind of grace under pressure, joking about the grimmest facts in his life. Otherwise, the programme seemed peculiarly graceless. For one thing, it was an inappropriate memorial on the anniversary of an atrocity, and then, right at the end, we were told that earlier this year an email claimed that Head had committed suicide. "It could just be one more story," said the commentary. "No one knows for sure what Tania Head is planning next." If she has killed herself, this was intolerably flippant. If they think she hasn't, what's the evidence?

When Secret Diary of a Call Girl was first published, there was some fuss about whether or not it was actually true. Were there really prostitutes who led such glamorous lives? Now we're on the second TV series, though, questions of truth and falsehood have been left far behind by the soft-porn stylings, contrived storylines and general air of smugness. This doesn't even have the sincerity of decent fiction; even Billie Piper doesn't seem convinced by it. She should make her excuses and leave.