CFA I post exam dilema

The other day I took my Level I exam, the exam went well but in the middle of the session the examiners told me that my username and passport did not match, but as they had let me sit down to do the first part I could continue. They told me that it was my responsibility to request the change at the CFAI but that they were not going to give any information about my passport or the incident to the CFAI (the center I was at did not scan passports). I believe the CFAI has no way of knowing that my name does not match exactly since my username is Will and my passport is William. However, I don’t know how to proceed, should I communicate this to the CFAI? I could continue without saying anything and then change my username to William once I have passed the exam without raising suspicions and having my exam invalidated? Thank you