If I understand your feedback correctly, I don't think that was a bug, but I also might be mis-interpreting it. On the last level, you're basically supposed to invert the left obelisk by unfreezing it while the button is pressed (which, like, "breaks" the cycle and inverts the button's controls) - if that's what you mean?
I don't think I conveyed the "toggle" nature of the obelisks well enough during the previous levels, which makes that final puzzle feel kind of like "I don't know why that worked" (and why it would kinda feel like a bug, heh).
Thanks for playing, and I'm glad you liked it! I really appreciate the feedback! :)