in the context of the NMC health scandal. I am required to identify and explain the possible threats to independence faced by its auditors, Ernst & Young which might have impaired their objectivity and professional skepticism, resulting in the audit failure. using appropriate and relevant examples/case studies to justify your argument.

I've written about the possible familiarity threat caused by having former EY employees on the board of NMC Health. what other threats may have impaired their objectivity and professional skepticism, resulting in the audit failure. Please explain using appropriate and relevant examples/case studies to justify your argument. Thank you!