Legislators expressed regret last night that the Airport Authority's working group had spared board members. Some members of the Legco Select Committee on the airport opening chaos questioned the independence of the group, noting that Billy Lam Chung-lun, the authority's acting chief executive, was one of its five members. Emily Lau Wai-hing of The Frontier said: 'It should have been dealt with by people untainted by this. 'Although Dr Townsend and Mr Oakervee have already left their posts, we feel that the Airport Authority should at least show their disapproval by severely reprimanding them.' Ms Lau and Lee Wing-tat and Sin Chung-kai of the Democratic Party related their dissatisfaction to Mr Lam. Mr Lee said: 'The report was unable to solve the key question of responsibility.' Both Ms Lau and Mr Lee pledged to follow up the issue by demanding an account at the economic services panel or setting up a working group under the House Committee. Mr Lee said he would invite working group members such as Maria Tam Wai-chu to come to the legislature. 'Ms Tam should explain how they arrived at the conclusion to lay all the blame on the staff. It gives people an impression that none of the board members has done anything wrong,' he said. Cheung Man-kwong of the Democratic Party said: 'I can't understand why Billy Lam was spared.' He said gratuity payment should be linked to performance. Edward Ho Sing-tin of the Liberal Party said the authority should take action in response to the Legco select committee report.