Josef Fritzl was the kind of character who believed he was never wrong, his lawyer has told the BBC's Richard Bilton.
Fritzl lawyer on plea change
Rudolf Mayer said 73-year-old Fritzl had one mindset: "I must always be full of power."
But after watching the video evidence of his daughter, he cracked.
"He was really destroyed in his emotion," the lawyer said outside the courthouse in St Poelten, west of Vienna.
"It was possible for him to feel for the first time the feelings of his daughter."
Even so, the decision to change his stance and plead guilty to all charges "surprised" Mr Mayer.
"I didn't know that he would plead guilty. A man of his personality always wants to be powerful.
"I was very surprised it was possible for him to speak to the whole public about how guilty he is."
He blamed that characteristic on Fritzl's childhood and the way he was dominated by his mother.
Mr Mayer said Fritzl appeared "happy" when he left the court after his change of pleas on Wednesday, saying his client hoped the full confession would "help the victims".
At the beginning of the trial, Mr Mayer had asked the court to see Fritzl as a human being, not a monster.
And still today, he would not accept a reporter's suggestion that Fritzl was the most evil person he had met.