People who preach about politicians lying are liars themselves — we all are
The Commons, particularly the Conservative side, is in a chronic state of shock: Imagine. He LIED to us.
It's a bit like the Profumo affair, where Profumo got his walking papers, not because he'd been bonking a prostitute who was also bonking a high-ranking Soviet official and perhaps pillow-talking national secrets to him, but because Profumo lied to the House about it.