the fairground is a voluntary temporary medical facility when you sign in you form an agreement to folow the rules, which are
leave if you want if not sick... but if you show symptoms your tested and given a further form to sign.
the guy actually signed a form when being tested saying he will stay until further notice while they test him and release him when cleared.
he wasnt cleared

yep he signed into the agreement to stay
however later he thought it was just a 72hour hold and thought he could just leave. and so he did.

my personal opinion.
maybe the form should be wrote in basic bulletpoint form (we all seen different form/contracts/agreements which have loads of wordy terms and conditions not layed out plainly in our lives right)

but not reading terms/conditions doesnt absolve you of the agreement(phone contracts are the worse)

in short be careful what you agree to