A person does not commit an offence under subsection 631(1) or (2), and is not liable under section 670E for a contravention of those subsections if the person proves that they could not reasonably have been expected to comply with those subsections because:

(a)

at the time of the proposal or announcement, circumstances existed that the person did not know of and could not reasonably have been expected to know of; or

(b)

after the proposal or announcement, a change in circumstances occurred that was not caused, directly or indirectly, by the person.