This is all just a war of semantics by Joyce as he clearly had his mind made up and has continued through the current union negotiations.
The term that applies is :"Deceptive by omission".
Re the Board if he didn't need their permission, why did he call a meeting???There is something seriously wrong with Governance at Qantas if his account is correct.
It is not what he said but what he didn't say that changes the whole context of the message conveyed.
Liability...you bet.