The question on the intent to earn money will determine whether you pay self-employment tax or not.
The question for you is whether the "contract fees" were a business venture or work of some kind or not. If it was a business venture or work of some kind, then you should likely pay self-employment tax.
If the contract fees were unrelated to work or a business venture, then you should not be paying the self-employment tax.
If you answer the intent to earn money question with a Yes, you will pay self-employment tax. If you answer the question with a No, you will not.