A 28-year-old woman presents with acute onset of severe left ankle swelling, erythema, and warmth following a minor ankle sprain 12 hours ago. Temperature is 37.8°C. On examination, the ankle shows pitting edema, and the skin overlying the joint is warm and tense. A needle aspirate from the joint fluid shows clear fluid with 3,500 WBC/μL (90% neutrophils), negative cultures, and no crystals. Plain radiographs are normal. The patient is started on NSAIDs and ice therapy. Histologically, acute inflammation is characterized by exudation. Which of the following best explains why the joint fluid in this patient is clear rather than purulent, despite significant neutrophilic infiltration?