LOL Teak.. Personally I think your friend might do better scamming insurance companies by having you steal his car or burning his house down ;) Either that or this could be your big chance to invent a cure for HIV!
This is an interesting question, if a bit strange. I know of no way to "beat" an HIV test. If your friend is HIV positive, he or she will have antibodies to the virus in the blood. These will be detected by the test. Alcohol will not obfuscate the results. Nor will anything else I know of. Short of providing some else's (HIV antibody free) blood, your friends, should he or she have HIV, will not "pass" the test. Of course, I assume that the insurance company in question will be performing an antibody test. Same answer applies if they use a virus amplification test (PCR).
How about finding a life.