I think you're right. I've never seen a crank sprocket marked way down low like the one that's at 12 o'clock. All of them I've seen are at between the teeth just like above your red dot. Good eye!
The issue is, if he uses that mark, it's gonna pull the piston well away from TDC. This is why I recommended finding true TDC and getting the degree wheel out, yet some of these guys on here just insist on plundering through the dark. This engine obviously has some incorrectly assembled and or incorrectly marked parts. It would be very easy to align everything properly and even remark that crank sprocket and get it all right by simply degreeing the thing. Anything less is just bad advice.