If Luka were privy to the Wizard's thought process here, he'd most definitely take issue with them assuming he might be a bad liar. The audacity!

But, unfortunately, Luka isn't a mind-reader. He instead flusters a bit when asked to explain himself.

"I don't... know." He says, uncharacteristically unsure of himself. He knows he can't change anything here, not really. "I don't want you to hurt them. They're a person, with thoughts and opinions - like me, or you."