Ms Weastell filed an employment tribunal claim against the council and Cllr Aspden on December 10 2019.
On February 17 2020 a meeting of the council's Staffing Matters and Urgency Committee was held. Press and members of the public were excluded from the meeting, at which a £400,000 payout was agreed for the former chief executive.
Cllr Aspden chaired the meeting and did not declare a personal interest, despite being named on the employment tribunal claim. Auditors say not all members of the committee were aware Cllr Aspden had been named on the claim.
Ms Weastell's final day of employment at the council was March 16 2020. The council released a statement on Ms Weastell's final day confirming her departure had cost the authority around £404,000 in line with statutory requirements.