No. 2 points is a lot at that level. If the commentator would think a move cost 2 points he wouldn't call it conversative but he would call it an error.
I think B actually results in more points overall, which is why it would play it; my curiosity is what fraction is due to direct effects vs. indirect effects.
For example, one could imagine the board position evaluation function being different for different timing schemes. If you're playing a blitz game where both players have 10 seconds to play each turn, some positions might move from mildly favoring black to strongly favoring black because white needs to do a bunch of thinking to navigate the game tree successfully.
It's no blitz game and there plenty of time to think through moves.
Just for the record at my prime I used to play Go at around 2 kyu.
There have been a couple of brief discussions of this in the Open Thread, but it seems likely to generate more so here's a place for it.
The original paper in Nature about AlphaGo.
Google Asia Pacific blog, where results will be posted. DeepMind's YouTube channel, where the games are being live-streamed.
Discussion on Hacker News after AlphaGo's win of the first game.