http://www.fatf-gafi.org/topics/high-riskandnon-cooperativej...
The FATF (Financial Action Task Force) co-ordinates AML regulations around the world. Note that Mexico is not on the list. Nor has it been there for a long time.
What's more, HSBC classified Mexico as standard risk but this did not override account level risk markers, it just meant they were not attempting to manually investigate every single wire transfer in or out of Mexico, an impossibly vast job. Wire traffic between US and Mexico is vastly larger than between, say, US and Algeria.
HSBC did not do anything wrong here.
For what it's worth, the 2009 IMF report on Mexico's FATF compliance[1] identifies a lot of issues regarding Mexico's AML process (see the ratings table starting at page 311).
Reading the Statement of Facts, I personally find the evidence compelling that there was a lot of blind eye turning at HSBC to say the least. Just one example:
When suspicious activity was identified, HSBC Mexico repeatedly failed to take action to close the accounts. Senior business executives at HSBC Mexico repeatedly overruled recommendations from its own AML committee to close accounts with documented suspicious activity. In July 2007, a senior compliance officer at HSBC Group told HSBC Mexico’s Chief Compliance Officer that “[t]he AML committee just can’t keep rubber-stamping unacceptable risks merely because someone on the business side writes a nice letter. It needs to take a firmer stand. It needs some cojones. We have seen this movie before, and it ends badly.”
(BTW I don't "keep saying this". It was my first comment on the topic. You probably confused me with milkshakes or dalke.)