I don't understand your link. Maybe other news now.
I do understand the word hostage and we went about that subject before.
Police is very careful in cases of industrial action. In Belgium there have been several cases of people who lost cases against union members when they drove through union pickets. Attempted murder!
But in this very particular case , it seems that you have not understood the concept of hostage.
If the story of Charlie Roy is correct ( I suppose so ) , please read again:
Security wouldn't allow me leave airside.
And he acted very correctly: just phone the police and say that "some people" keep you in a place and don't allow you to leave. That is hostage taking.
The opposite with industrial estate blockades isn't hostage taking. It is simply blocking entrance of goods or people. They can go where ever they want, their freedom is not obstructed.
There is a grey zone with security personnel. If by an industrial action, the security personnel acts very slowly and create by this a very long cue, hm, quite difficult to call it hostage taking. And if you skip the line and forcefully would try to get out, you break security rules. But again: grey zone. It is also a legally interesting subject in case security is subcontracted to a private company. They do not have the same status of state officials ( real police). Simply said: if a policeman instructs you to lay down on a wet floor to be padded, and you disobey and start to wrestle a bit, you get arrested on grounds of disobediance of uniformed policemen. If you refuse to be padded at an airport by security staff, and you are taken aside, they are already wrong: they are not allowed to take you, they can ask you. The only ones who are allowed to act "by force" are the real police.
But I would disadvice to try it out at the start of your holiday. You don't want to miss your flight ( not refunded!) , undergo a "deep cavity" search by uniformed police and be placed on a non fly black list.
By the way: in case of hostage taking, a citizen in Belgium is allowed to use any mean to regain his OWN freedom, including using lethal violence. But this doesn't mean you can try out martial combat arts on a union member who blocks the exit door. It is way simplier to form a group of collaborators and smash the windows by seats, tabels and chairs - as I have done in the past in non airline circumstances. Positive was that nobody got hurt ( union members always run away from scattering glass ), police didn't intervene because they thought it were the union mobsters who were smashing things up and it was in the days before small mobile phone camera's and other nasty security stuff that could give you a hard time in a court case.
Back on track: if Charlie Roy had no means to get his freedom because he was obstructed by security personnel, he was taken hostage. I do wonder if he filed an official complaint.