Industrial action shall not be regarded as having the support of a ballot if the following conditions apply in the case of any person—
he was a member of the trade union at the time when the ballot was held,
it was reasonable at that time for the trade union to believe he would be induced to take part or, as the case may be, to continue to take part in the industrial action,
he was not accorded entitlement to vote in the ballot, and
he was induced by the trade union to take part or, as the case may be, to continue to take part in the industrial action.