Ah sorry! You've done something here that we didn't plan for. Just pushed a level design fix, or you can undo past the checkpoint but it may not be obvious how far back you have to go.
You did indeed have to put the green key there earlier.
Now it checkpointed me like this, which would possibly be fine if I already had the green key recovered, but I haven't. (At least I see no way out of this that wouldn't just unrecoverably trap the yellow or orange key). I know I can undo out of it, but wanted to help make the checkpointing more robust.