what makes them not eligible?  CA has different qualifications for EITC than federal.

I understand the eligibility is:

To qualify for CalEITC you must meet all of the following requirements during the tax year:

• You’re at least 18 years old or have a qualifying child

The taxpayer was 70 years old and earned 1099-nec. Previous year CA sent a letter limiting the credit. 

He IS at least 18 years old, and he doesnt need a child to qualify.   

If hes self employed, sometimes CA sends out a letter "auditing" the business in order to give them the CAEITC, they ask for bank statements business lic, etc.  If he didnt reposnd they'll disallow the EITC.