actually the launch sequence kind of accounts for this, according to ryan the ride mechanics video on the hydraulic launch coaster, the launch sequence is the following:
magnetic brakes are lowered,
tires push train forward,
tires drop down and launch dog drops down on train,
train slowly rolls back into the catch car,
using a sensitive position sensor (capable of seeing where the train is over a distance to the mm) once the train is caught in the catch car the position is verified to prevent the launch dog from not being properly locked in,
hyraulic valves are opened, train departs station.
reseting it I would assume would be waiting for the train to return to the station, fixing the issue then engagine the hydraulics in reverse (they switch to neutral when stopping incase the train rolls back and the launch dog is dropped meaning it catches the catch car and causes lots of expenive damage) and making that return to its position as normal and launch again.