To count as earned income he has to have a net profit of $433 or more on schedule C for self employment income. It needs to be at least $433 to pay self employment tax on it. You need to pay self employment tax to count as earned income.
Then, If you have self-employment income you can only contribute to a IRA up to your net profit reduced by the deduction allowed for the ER portion of your self-employment taxes. See IRS publication 590A (page 39 for ROTH) https://www.irs.gov/pub/irs-pdf/p590a.pdf
