Back in Generation 2 (when the episode took place) moves were divided much more simply than they are now. All grass type moves at the time were classed as "special" moves, be it Vine Whip or Solar Beam, so at the time the episode was made, Brock was correct in what he said. They were divided as they are now in Generation 4, when Vine Whip became a "physical" move.
And Reflect blocks physical attacks, always has. You're thinking of Light Screen.