If you widen the threshold to include those who go overseas for their LLMs, the list gets longer.

Postgraduate degree in law
R&T: Lee Eng Beng (Oxford BCL)
Judiciary: Most High Court/CoA judges have LLM from Harvard/Cambridge
SMU: YH Goh (Harvard LLM)
NUS: Simon Chesterman (Oxford DPhil)
RHT: Walter Woon (Cambridge LLM), Roderick Martin (Cambridge LLM)
WongP: Tan Chee Meng (Cambridge LLM)
Essex Court: VK Rajah (Cambridge LLM)
Cabinet: Desmond Lee (Oxford BCL)
A&G: Stanley Lai (Cambridge LLM/PhD)

(Non exhaustive)