Incognito: I did not know this specific case of the corner with this "false 6-shape eye" equivalent to an exceptional "small eye shape" with 4 inside liberties only - Thank you for the lesson
Incognito: I found the glitch analyzing 5 or 4 officials answsers : in the left corner, it counts only 4 liberties with a "6-shape", but there are 12 (6-shape) - 4 = 8 liberties
d4rkm4tter: So this is not a 6-eye because of the corner, which is pretty neat I think.
By the way, if W last move to kill is F10, the approach at C10 is not necessary and should not be counted as a B chain liberty. Am I wrong ?