The CEO states that the flight was 'fully boarded' and then later that it was decided to 'deny boarding' to four passengers.
So was it fully boarded or not? It doesn't really matter, the airline can change its language as it sees fit, to achieve its desired business objective and the customer has no recourse.
I'm an aviation enthusiast but I don't fly commercial airlines any more for this reason amongst others.
[0] Because when there's no safety risk they can just escalate until the customer becomes aggravated, and then there's a safety risk.