Well they are indication, just not conclusive evidence, since they can be natural or faked (at a cost)
smooth in Bill Clinton mode.
They can also be an indication of deception to confuse when there are actually attacks ongoing, which was CfB's correct point.
Good thing we do not have any such confusion then!
It seems no one is interested in spending money to create confusion about attacks they aren't performing.
But lack of ephemeral forks is conclusive evidence of lack of an attack, subject to the (reasonable) conditions I stated above.
Wrong again. Example, Finney attack. Example, a double-spend that falls within the expected number of confirmations of normal orphan rate.
A Finley "attack" does not exist in the system as defined by the white paper, where PoW defines ordering (as opposed to mint timestamps as described in section 2). If people want to be dumb and rely on zero conf in Bitcoin, they are attacking themselves.