During his testimony, Tam described Choi's former in-laws as "horrible and ungrateful" following a significant family dispute. He also provided insight into his own complex relationship with Choi and Alex Kwong Kong-chi, a former classmate.

The court heard that Tam, Choi, and Kwong remained connected due to their four children. Choi had two children with Tam and two children with Kwong.

Tam's testimony was presented during the third week of the murder trial.