He said: "You don't have to keep going back to someone who knows what the criticism is. They don't have a right to approve wording. They have a right to know what criticism may be made of them and to make representations."
Mr Randell worked at law firm Slaughter & May from 1980 to 2013, becoming a partner in 1989.
He specialised in corporate finance law, and worked on financial stability and bank restructuring assignments.
He advised HM Treasury on the resolutions of Northern Rock, Bradford & Bingley and the Icelandic banks as well as the government's investments into RBS and the merged Lloyds/HBoS.
Mr Randell also advised the Portuguese Ministry of Finance on the recapitalisation of the Portuguese banking sector.