I'm guessing that while they "technically" didn't get 51% of the hashrate, they still did accomplish what a 51% attack would have achieved. While some people are claiming it's "lucky", it happened, they rewrote 6 blocks by secret mining and replacing the main chain. It's still a great example of exactly what we are wanting to avoid. I wish that we would stop closing our eyes and ears to this simply because they didn't hit the "magic number" we deem is worthy of concern.