Since when has Pontoise been in Paris and I can just imagine a full load of 19 punters arriving at the check-in desk at STD -15 and all being processed in time for an on time departure!
In fairness,
Phileas, if you'd ever flown scheduled out of Shoreham then you'd know that's quite possible. When I used to fly ESH-ACI regularly it was quite possible to get everyone processed and off in time for the flight even if they did all turn up at the last minute.