"I am an ATC and the transcript also surprised me.
I guess the problem is that it is a translation from English to Chinese and then to English. However, the lack of read back is not explained by incorrect translation."
I lived in China (next door to the Air China Airbus rep - thereby hung a few tales...) for a few years. Believe you me, a translation into and then out of Chinese, a language very different to English, can very easily explain the lack of read back!