I know, I was there - Said when someone is being a stubborn idiot and won’t accept

Said when someone is being a stubborn idiot and won’t accept the truth, even though it was right in front of them.

'I know, I was there,' he said, even though the evidence was clear.

'I know, I was there,' she said, even though the teacher told her she was wrong.

'I know, I was there,' he said, even though he was the one who messed up the math.