Intent doesn't need to be proven. If you knew of the material non-public information and you then decided to execute a trade you're guilty of insider trading.
It would be highly unusual for the CFO not to have the burden of confidence but even for a division president it's not clear they'd have corporate officer responsibilities.
During compliance training in my old life they covered the classic "overheard in a coffee shop" example as a way to highlight that a barista does not owe confidentiality to a random public company. However, I don't think it's ethical behavior regardless of whether it'd result in a conviction.