Unless you specifically drove into a chargeable drop off zone (which exist at some airports) and have to be well signposted, then it is always no.
Ever since the Shoe Lane parking case which got right up to the the then Master of the rolls (Lord Denning) you are entitled to read the parking terms and conditions and if don't like them exit the car park. Therefore all automatic (non manned) car parks let you drive back out and will open exit barriers, with the unpaid ticket. Normally is within 5 minutes of entering. This is rarely advertised on the displayed charges board as getting X minutes free.
It is because it is not usually possible to reverse back out (one way, and cars behind) so always able to drive through and straight out again.