Yes, you made a mistake. Any sort of reddit advice should always be qualified with "Your milage may vary" because there are few rules that are universal.However once you mentioned the interviewer was "getting annoyed" you were probably done, since the HR person probably flagged you as difficult/ refused to answer "simple" questions.

Once it started into a back and force you should have either answered.

1. If your state allows them to validate it with your current employer: then you should answer honestly.
2. If your state doesn't, then you could give a number which "is in line with market rate for your responsibilities and experience"