Vortex - my very first student as a baby B2 QHI at SARTU (1989) decided he definitely didn't want SAR post Shawbury - his flying was fine over land but went to pieces inexplicably over the water. An overheard comment from one of his course mates led to the penny dropping for me - he had deliberately failed the sortie. After a firm debrief in which he was reminded that if he didn't pass SARTU, he didn't get his wings at all, suddenly he was good as gold again.
Baldeep - good post