Kevin Rudd had no alternative. He agreed to the debate and tried to neutralise the Coalition tax package, claiming he and Swan had been working on theirs for months.

One way to find out who’s copying your confidential documents is to insert some sort of trap. Peter Costello dropped a bombshell on Insiders yesterday when he revealed that under Labor about 45% of taxpayers would pay substantially more tax. This is because the threshold where the marginal rate increases to 30% will be $41,000 under the Coalition package, but $37,000 under Labor’s. Explaining he couldn’t put everything in the media release, Costello said anyone who knows anything about tax would have been able to calculate the threshold from the goal that 45% were to be on a marginal rate of 15%, which is right. Labor walked into that one.

Barrie Cassidy often allows politicians so much leeway it’s only the prospect of the panel debate that keeps many viewers tuned in. This time he was impatient with Costello, interrupting him frequently. While understanding Labor’s blunder takes concentrated analysis beyond the evening news, the message the Coalition puts out will be simple: $600 more tax each year under Labor.

Rudd could fix this up by just changing the threshold. But then he’ll be admitting Labor had no tax policy, cribbed the government’s, misunderstood it and the “cost” of theirs is higher than they claimed. Most in the media played down this serious blunder, but if Treasury agrees in its independent assessment, this will come back at the end of the campaign. So don’t be surprised if the thresholds are quietly changed on a busy news day. In all this, Costello has demonstrated, as he does in Parliament, that he is a formidable opponent.

As to the debate, not much was made about the fact that Howard had the cabinet there, but where was shadow cabinet? Is Rudd trying to hide them? David Spears emerged as by far the best chairman yet seen. The panel redeemed something of the reputation of the gallery which has so far given Rudd a dream run, just as they did Latham – remember the FTA?

The weakest answer on campaign issues was Rudd’s failure to provide any carbon emissions targets for his first, second, third fourth or fifth terms, if they eventuate. Rudd is usually more careful, setting up some long often convoluted process to find a solution well down the track. On emissions he foolishly announced the long term solution first – a massive reduction – and then tried the impossible – to work backwards with an inquiry into the costs of the policy and the targets to be achieved by a Rudd government.

Nine shamelessly breached transmission conditions by running the worm, and then made fools of themselves by once again botching the selection process. The “undecided” worm yielding claque voted a ludicrous 65:29 for Rudd. When the worm has done this in the past, the “loser” has gone on to win the election. The commentariat gave previous debates to Latham and Beazley, but the fact is that determining who wins is just a personal opinion. To portray someone’s opinion as fact in the news shows how far the media has gone in abandoning the fundamental a rule that comment must be clearly distinguished as such.

I happen to agree with Glen Milne: both performed well, but on substance, Howard won. His daughter preferred Rudd’s tie, but I am afraid I didn’t notice that.