There is another test available which looks for the viral load - ie: the amount of the live virus present in a person's blood stream. This test is not widely used because it is far more expensive and takes weeks rather than days for a result to show up.
The standard HIV test looks at the antibodies present in the patient's blood. All this tells us is that this person has at some stage been exposed to HIV and developed an auto immune response to that virus. Research thus far would seem to indicate that many people who are exposed to the virus have been able to suppress its progress. Those who go on to develop full blown AIDS have not been able to do this. It would appear that a raft of underlying health and lifestyle issues, including the history of other sexually transmitted diseases, general health and nutrition are factors in this difference. This is why HIV/AIDS has been so devastating in developing parts of the world.
The viral load test is a far more reliable indicator of how infectious the patient actually is.
I would point out however that not disclosing one's HIV positive status to a prospective sexual partner is an immoral act, as it takes from that person the power to make an informed decision about the risk they are taking. It is not however one which I would say deserves a 37 year gaol sentence. After all, each participant in the sex act had the opportunity to insist on the use of a condom without reference to the HIV status or indeed the general sexual health of the other.
You know condoms also protect against chlamydia, Gonorrhoea, genital warts and syphilis - none of which are pleasant and all of which have life long baggage associated with them.
If you can't be a good example, you'll just have to be a horrible warning.