Neil deGrasse Tyson was not at the IAU General Assembly and therefore did not vote at all on the Pluto resolutions.

The statement "Pluto's no longer a planet" is not a fact; it's one interpretation in an ongoing debate. Time magazine should treat it that way. Professor William B. McKinnon has a podcast on the Sky and Telescope web site that provides a different view:
http://www.skyandtelescope.com/skyte.../38235059.html