I was apparently one diamond short of opening the passage in the blue area, and managed to single-shot blast myself into the hole to the purple zone. I have no way out now. Whoops
I forgot I was actually on twitch when I did this one. I was offline when the other bug happened... but I got lucky jump here in a highlight: https://www.twitch.tv/videos/2097885226
I'm that stubborn idiot that will sometimes try repeatedly to do the "nobody's gonna do that" thing just to see what happens. This time it wasn't intentionally me being a dink, though. I had one diamond left to find and I knew that section down there hadn't been cleared yet. It was the only place I could think of, and the challenge at that point (for me at least) was roughly where that leap of faith seemed like a good potential for where I needed to go... until I got there and cooked my savegame lol.