Contravention did not occur.
The second case you cite you have picked out the wrong part - it's the last point about free parking you need.
I would also say something about the council's rejection. which refers to no valid parking session, but the contravention is not paying for parking. They could have issued a different contravention of no valid P&D 'display'.
I would also say you did activate the free hour and provide proof as that shows you had an hour in mind.
Much depends on the adjudicator but at least if you get one of the tough ones you can evidence other cases.