[forum456]

"A" gives bribe $500 => to "B" , then,
 "B" quietly returning $200 => to "A" personal account.

But "A" looks honest and innocent

Hahaha Only God knows

US court already knew about this and had evidence to charge him.
you have the full story of how the corruption happened

this is not new case for CPIB.
all evidences and happenings are known in US court.
CPIB just needs to use US evidence and the paper trail to re-construct new evidence without the help of witnesses