although the experts providing live public commentary on the match weren’t clear on the matter
This could be motivated thinking/speaking though.
I watched the whole of both games played so far. In the first game, Redmond definitely thought that Lee Sedol was winning, and at a point close to the end, he said, "I don't think it's going to be close," and I am fairly confident he meant that Lee Sedol would win by a substantial margin. Likewise, he definitely showed real surprise when the resignation came: even at that point, he expected a human victory.
In the second game, he was more cautious and refused to commit himself, but still seemed to think there were points where Lee Sedol had the advantage. However, in this one he did end up admitting that AlphaGo was winning long before the end came.
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.