Whoa, this is confusing as hell. Not that I can doubt you, but:
People interrupt with D1 all the time. Pig was doing it to Tom in the video they've posted, and I've been playing Lao for a year now under the premise that it CAN be interrupted and has been interrupted numerous times.
In fact, someone just demonstrated how you can interrupt it with Smoke and linked a video to it in this very thread. I'm pretty sure
UsedForGlue has talked about how it can be interrupted for a while now as well.
Hopefully the confusion can be clarified, and thanks for the input.