OAONAN RCD plug teardown and schematic

A cheap RCD plug being sold by Amazon. How bad could it be?

00:00 Index
00:10 Introduction: OAONAN RCD plug
00:26 Non-compliant mains plug and no fuse
01:38 Cord grip? What cord grip?
02:04 Testing the RCD
03:12 Off with its plug! What's the cable like?
03:31 What's inside?
04:25 Board close-up and schematic

There's an error in the schematic. The test wire should go from D1, through the coil then to R1, from the output side. In the schematic shown the test current would cancel itself out unless the wire was wound in the opposite direction (which would double the apparent current instead).