The monitoring was part of a five year "deferred prosecution agreement" with the DoJ which allowed to bank to avoid actual criminal prosecution and so continue to operate in the US unhindered.
Later, in 2021, the Guardian reported[2] that HSBC became aware as early as 2016 of a money laundering network "involving 92 HSBC Hong Kong accounts that received $4.2bn worth of payments between 2014 and 2017":
> The bank, which is headquartered in London, would have been expected to disclose the information to an independent monitor brought in by the US Department of Justice (DoJ) in 2012, when criminal proceedings were deferred on condition the bank reform its anti-money laundering checks.
However, while anonymous monitoring team members told the Guardian they had heard nothing of the $4.2bn network, HSBC remained coy:
> HSBC said in a statement that it was illegal to disclose information it had shared with government authorities, and said “specific discussions with our former monitor remain confidential”.
In charge of monitoring HSBC's deferred prosecution agreement was one Lisa Osofsky, a compliance expert and investigator working for Exiger who'd spent three years with Goldman Sachs and seven with Control Risks[3].
Doubtless Osofsky's investigatory skills and robust approach to financial regulation were factors in her 2018 appointment as head of UK's "Serious Fraud Office" (UK's FCC, kind of).
According to HSBC whistleblower Nicolas Wilson[4], as of July 2021 Osofsky was living with her husband in a £3.5m London flat "with an HSBC mortgage".
1: https://www.theguardian.com/business/2012/dec/11/hsbc-bank-u...
2: https://www.theguardian.com/business/2021/jul/28/hsbc-faces-...
3: https://en.wikipedia.org/wiki/Lisa_Osofsky
4: https://twitter.com/nw_nicholas/status/1420692450260172803