Yes its legal to omit test results, diagnosis or even that you committed a crime from public and private records. lawyers do it all the time. they defend mentally ill people and omit deflaming information about their clients. lawyers defend criminals that committed crimes and even if the person says to their lawyer yup I did it. that lawyer has to go forwards and defend that rapist, murder as if they never confessed or remove theirself as their lawyer. Lots of times too when a lawyer finds out their client has a problem that would cause problems with winning the case the lawyer puts a gag order on the doctors preventing them from disclosing certain information. Doctors too omit information all the time. when I moved here for college I had to have a local doctor and therapist in case I had any problems here. my doctor only sent partial records that was just about the problem I was having at the time I needed a local doctor and therapist. he didnt send my whole 15 year record he has on me. My mom had a child out of wedlock and the child placed for adoption. my moms and that babys records dont list my mom as the babys mother and my moms file doesnt have anything about giving birth to that baby at all. There are lots of reasons why doctors and lawyers omit stuff from files. even mental places omit things from the files. Here at the crisis center where I do my part of my internship we dont keep detailed files on all the client cause the files could get pulled into court if the client is prosecuting. My therapist doesnt keep detailed files on me either. and sometimes I have to "refresh" my therapists memory on something I told her cause she didnt put it in the files and didnt have it to look back on right before seeing me.