Well, you have two options:
1) Wait to see what else they require from you to complete processing and unfortunately, I cannot tell you how long that will take, or,
2) Withdraw the visa application, have your brother file an I-824 with USCIS to restart the process to get the visa (no, you do not have to wait for a visa to become available again that took many years, this is just to restart the process at the U.S. Embassy or Consulate).
The problem with #2 is that because we don't know what else they need or what is their concern, restarting the process to get the visa may run into the same problem as you are having now. So it is better to just wait. They may have a concern that because you had something related to alcohol in 1992 and another in 2008 that you may have an alcohol abuse issue. Or if you failed to disclose either or both issue, you could have an issue with misrepresentation. So we have to wait and see.
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