Rudd was always hawkish, he just hid it better when he was PM. The Chinese are not naive either, they know what Rudd is like.
Somewhat agree. To foreign audience, in the beginning when he got elected as PM, he was seen as some kind China relations expert with a non confrontational tone ( of course at that time, China aussie relations were good, pretty much close to peak before it went downhill and then crashing at late Obama, early trump era. With his diplomat background in China and speaking fairly decent mandarin by laowai standards, that interview of him in Mandarin got plenty views in China.
He was later exposed as two faced by domestic media when he called out China officials as rats for killing his climate change deal, behind closed door. But this story was not widely circulated internationally so it kinda passed by. At this point he was not hawkish though, I still reckon he was more interested in engaging China, he wanted Australia to be some kind of middle power, meditating China US influence. He slowly turned more anti China I believe after he left Aus politics to get the cushy job in US as Australia representative.
While he is not as anti China fanatic like Dutton or Morrison, he also certainly isn't in the pro China side like the retired PM, Paul keating.