A 42-year-old woman from Mumbai undergoes femoral artery catheterization for coronary angiography. During the procedure, the interventional cardiologist notes that the femoral artery puncture is slightly medial to the usual site. Post-procedure, the patient develops a pulsatile mass in the groin with a continuous 'machinery' murmur on auscultation. Duplex ultrasound confirms an arteriovenous fistula. Which vein was most likely injured during the arterial puncture?