You could even say that “could” for an action is always defined relative to the agent who takes that action, in which case I can simultaneously make the following two statements:
NonSuicidalGuy could jump off the cliff.
It is impossible that NonSuicidalGuy will hit the ground.
Isn’t that a logical mistake, though? Fow that to be correct, it must be that NonSuicidalGuy will hit the ground if and only if he chooses to jump off the cliff.
Have you ranked questions by their easiness before you looked at the results?