Why is a generally upright but less precise narrator’s version not automatically hasan if it demonstrably contradicts a better-preserved report?

Hasan li-Dhatihi, Sahih li-Ghayrihi, and al-Tirmidhi’s Composite Terms

• Every variant is intrinsically defective and irreparable
• Uprightness makes analysis of contradiction irrelevant
• Because anomalies and hidden defects still require investigation
• Contradiction analysis is only needed for fabricated reports