Yes, it can be opened with one hand
I've read a lot of reviews complaining about how the Spatha can't be opened with one hand. I almost didn't buy it because of these reviews. But, I found a good deal and bought it anyway. Happily I discovered that you can, in fact, open it with one hand quite easily. You hold the center ring, where the carabiner fits, and catch the bottom against anything, your thigh for example, and it opens right up. You can't grip the blade with your fingers and wrench it open, as you might with other knives. But once you figure out how it is supposed to be opened, things make a lot more sense. All in all its a great little knife and I'm glad I bought it.