Tom Sutcliffe: If it was a job interview in front of the nation, the vacancy's still open

"It will disappoint you and it will disappoint many people but we have come to the end of our debating time," said Alastair Stewart, wrapping up Britain's first television leader's debate. It wasn't the first prepared line that failed to match the mood of the moment but it surely offered the biggest discrepancy between wishful thinking and hard fact.

You couldn't really say what the audience in the studio were feeling – struck dumb, as they were, by obedience to the rules – but it was difficult to imagine an outraged clamour arising from the sofas of Britain – "Oh no! Not already! I could happily have taken another hour of that!" And for the participants, as Stewart must have known, there can have been nothing but relief in the knowledge that the sudden-death penalty shoot-out was very nearly over.

None of them had conspicuously missed a goal. That would have been far too exciting, and almost certainly in breach of one of the 76 regulations which ensured an event that seemed very unlikely to act as a political aphrodisiac on limper elements in the electorate.

On a couple of occasions Nick Clegg had been startled by Alastair Stewart's off-camera barking – finding himself back in the limelight and forced to say again, in slightly different words, what he'd just said a minute previously. Gordon Brown made an ill-advised attempt to work in some humour – dropping in lines greasy with the hands of many speech-writers. "You can't airbrush your policies even though you can airbrush your posters," he told Cameron, with one of those unnerving YouTube grins.

Cameron, like the others, began a little uncertainly, breathless under the weight of memorised facts. But nobody did themselves lasting damage – or, I would have thought, a great deal of good either.

Nick Clegg, seeking our votes for the Neither-of-the-Above party, was at pains to include both other men in his answers. Cameron mostly ignored Clegg for frontal assaults on Gordon (they were all on first name terms). And the Prime Minister used the phrase "I agree with Nick" so frequently that you wondered whether he might do a power-sharing deal live on air. The Prime Minister, conspicuously, was the only candidate who'd steered clear of a party colour tie – edging away from scarlet towards fuchsia. Perhaps there was some subliminal message here about the bright fuchsia he could offer to the people of Britain. Perhaps he simply understood that Labour branding wasn't his best available asset. In terms of departure from expectation though that was pretty much it.

Anyone hoping that the volcanic ash of those pre-arranged regulations wouldn't ground the thing before it even took off would have hoped in vain. There was one little ripple of studio laughter – after Cameron had licked into Clegg on party funding – and one inadvertent reaction shot, when an audience member was caught enthusiastically nodding at a Cameron rebuttal of Brown. But otherwise everyone was horribly well-behaved. It was like a 38-round bout, in which every fighter was wearing head-guards and there wasn't a single knockdown.

One punch did connect though – not because of rhetoric but because of a recognition that the same figure can look very, very different depending on how you phrase it. The Conservatives want to take £6bn out of the economy, said Gordon Brown – knowing that the scale of that figure will stir voter uncertainty about the impact on the economy. Cameron replied that his party was seeking to cut just one pound in every hundred the government spends – an economy that sounds so modest and achievable that very few voters will think it counts as recklessness. Labour spinners might want to work on a way of rebutting that neat trick of perspective if they can spare time from preparing for next week's debate. "It's like having one big huge job interview in front of the whole nation," Cameron said before the broadcast. On the evidence of last night the post's still open.