Actually, from the left lane at the roundabout, you are always supposed to turn into the first lane (on the left) of the first exit. But Benz should have gone straight only, unless specified on road markings/direction signs. One thing wrong about HK road markings, is that they are wrong or non-existent! In particular at roundabouts, and it just makes drivers in HK even more unknowing of the rules when approaching a roundabout.

出街最驚遇到呢D"車手"
呢個迴旋處轉左新畫線好耐啦
仲有好多人要做外圈L..好彩今次避到