To be fair, Howard wasn't saying the attack weren't racist he was saying there isn't a problem racism "in general" in Australia i.e.,

'Attacking people on the basis of their race, their appearance, their ethnicity, is totally unacceptable and should be repudiated by all Australians irrespective of their own background and their politics,' he said.

'I believe yesterday's behaviour was completely unacceptable but I'm not going to put a general tag (of) racism on the Australian community.'

Of course, he would say that because that might mean he should do something about it. After all, who do they racists vote for?