As I have often said on this topic, even if he were right, it would mean things were irreverible and there would be no point at all to so-called GHG emission controls.
Only melting of ice on land would have the effect of raising ocean levels, which is mainly continental Antarctica and the Greenland ice cap. They would create a rise on that order if completely melted, from what I have read.
However, any floating ice including the Arctic ice cap or the Antarctic ice shelves would have no net effect at all, they are already displacing as much water as the amount they would yield if melted.