A pundit is someone who offers to mass-media his or her opinion or commentary on a particular subject area (most typically political analysis, the social sciences or sport) on which they are knowledgeable.

Greenwald seems pretty clearly to be offering commentary on these events, and not just straight fact/story-reporting.

How much you like him or find him honest doesn't change what you call what he does. You can set him apart from other "pundits" but it's hard to say he isn't commentating or offering his opinion.