I was tuped years ago, the md and hr manager sat us down one by one and went over the new contact and the changes. Explained the pros and cons ect.
I thought it was a good way of doing it as i may be able to fix a fridge but understanding legal terminology is a different ball game.
The security Gaurd needs to fight his case. Acas will be able to advise him, I have seeked advise from them in the past and they really are good. Not one sided and put it all in laymens terms.