The transcript of what KL said is:
“Let’s remember when Hitler won his election in 1932, his policy then was that Jews should be moved to Israel. He was supporting Zionism – this before he went mad and ended up killing six million Jews.“
So he didn’t say Hitler was a Zionist just that he supported Zionism. This was part of The Haavara Agreement. Zionism as a political movement was for the establishment and self-determination of a Jewish state, Hitler wasn’t about that. It was most likely political expediency to give the Nazis time to come up with their abomination of a “final solution”.