I have no recollection
A way to pretend you never saw something, even if you were there when it happened and you remember everything else.
The witness said, 'I have no recollection of seeing the murder,' even though he was holding the knife.
The friend said, 'I have no recollection of borrowing your pants,' even though he was still wearing them.
The kid said, 'I have no recollection of stealing the pizza,' even though he had a slice in his hand.