The indictment in HSBC is full of stuff like "HSBC ignored government recommendations that Mexico be treated as a high-risk area instead of a medium-risk area..." This indictment has deliberate, knowing activity on the part of Shrem that, as the e-mails indicate, even he thinks is illegal.
'In some of the documents, prosecutors allege that HSBC intentionally flouted the law. The bank created an operation that was a "systemically flawed sham paper-product designed solely to make it appear that the Bank has complied" with the Bank Secrecy Act and is able to detect money laundering, wrote William J. Ihlenfeld II, U.S. Attorney for the Northern District of West Virginia, in a draft of a 2010 letter addressed to Justice Department officials.'
'In one email exchange submitted as evidence in that case, employees debated whether the bank should help a Miami client get around U.S. sanctions by moving the client's business to HSBC's Hong Kong office. "I believe that the best outcome would be for the customer to open a relationship with Hong Kong just for leters (sic) of credit purposes. He travels there all the time," private banker Antonio Suarez wrote in a 2008 email. Suarez has since left the bank and couldn't be reached for comment.'
http://mobile.reuters.com/article/idUSBRE8420FX20120503?irpc...
From the indictment: "Shrem email accounts reflect that 'BTCKing' not only obtained his supply of Bitcoins through the Company, but did so with extensive support from SHREM."
If the DOJ had an e-mail trail of anyone important at HSBC giving personal technical support to a drug cartel, the outcome would have been very different. Remember, "allegations" are just that, and there is a gap between what the prosecutors might allege and what they can prove in court. The proof in this case is a slam dunk. It combines explicit support for BTCKing with explicit knowledge of his illegal activity. In HSBC's case, that link is missing. You have emails like the one you quoted, which could be interpreted as wrongdoing, or could just be interpreted as figuring out how to let a client do what he wants in a legal way by dealing with a different office.
The only thing they didn't do is advertise directly to drug kingpins. Then again, we don't know that they didn't.