acting clinton foundation ceo maura pally said ` yes , we made mistakes '
fund ` mistakenly combined ' government grants and other donations .
foundation faces criticism after report it received millions from executive who sold uranium company to russia in state department-approved deal .
pally said canadian law prevented its partner from disclosing the donation .
took in $ 140million in 2013 and spent on $ 84.6 million on payroll and operations and just $ 9million on direct aid .