Reason to appeal test

Hi, my daughter failed her test this morning and were considering appeal.

As she drove towards a roundabout junction she began to apply the brakes in order to slow down/stop, however whilst she was applying the brakes the examiner jump on the brakes for no apparent reason and she failed.

There were no people around or animals and plenty of room in front to bring the car to a halt.

Is there grounds for appeal based on this?

Thanks