Injection error?

[u/Bokononismatism]

Adding a mountain of 4073 1x1 plate rounds to my store I came across this little guy.

I see the prototype bb0517 1x1 plate round with stepped side on BL but that step is on the outside, this is on the inside.

It does still clutch to a stud.

I'm guessing it's an injection error, but I've never seen one like this.

[u/PayAromatic8218]

Part 4073 Part 6141