The evidence for his death at Seven Pines is so strong, in my mind, that if I were you, I would take that as fact with perhaps only a tiny asterisk noting that the information came, not from CSA records, but from family.
Reasons:
1. The first Battle of Bull Run, or Manassas, is precluded from consideration since it was fought July 21, 1861, and records indicate that Sturkie was alive and apparently well on April 17, 1862, when he was discharged and returned to duty from General Hospital No. 18 in Richmond, after treatment for chronic rheumatism.
2. Second Manassas (Bull Run) is also precluded since his unit was not in that particular battle.
3. His family stated that he was killed at Seven Pines, a battle in which his unit suffered a great number of casualties.