There wasn't any permanent marking going on, just pointing out. It's the same thing unless there is a rule that differentiates the two.
If he left his finger there, I can see the discrepancy, but it was coaching which is allowed.
Like the poster above asked, are there a mosconi cup set of rules for match play?
I agree, that's my point...that's why Corey told Shane to back away, because Shane was leaving his finger at the spot until Corey shot.