Based on various Rev. Rulings, the bar for when net earnings from an activity would consistent self-employment income subject to SE-tax is lower than the more stringent considerations for §162 trade or business.  As a general rule, the taxpayer would be deemed to be engaged in a trade or business for purposes of §1402 and §1401 if he/she engages in the profession or occupation for profit and with sufficient regularity but not as an employee.  So, it is ***possible*** for income reported on 1099-MISC to be reported on Line 21 but still be subject to SE-tax.

In this particular case, assuming the taxpayer is indeed an independent contractor and she pursues similar opportunities on a recurring basis, it could be difficult to argue that the income should not be subject to SE-tax given the profit generated in spite of the activities not being continuous and substantial.