Whilst it makes sense for Examiners to check licence validity, the requirement to do so was only added to the Examiners' Handbook after this accident. At the time of the LPC in question, I believe that no such requirement existed.
Second, the inclusion of expiry dates in Private licences was a sneaky money making twist introduced during the JAA debacle. Previously PPL's had been valid for life and the design of the licence using a single two sided folded sheet meant that the expiry date was often hidden inadvertently. Many pilots presenting themselves to me for an LPC during the transition period had never even noticed that their licence had suddenly grown an expiry date. There are still a number of UK PPL's out there with no expiry date.
Third, even when a pilot has passed his licence expiry date, he needs to complete an LPC in order to revalidate his licence. Whilst examiner action required is different, there is nothing to prevent the LPC from being completed.
The real question here is one of Pilot responsibility. As the Commander of an aircraft, the Pilot in Command is soley responsible for ensuring that they are legal to fly every time they take to the air. Pilots should not even be presenting themselves for an LPC unless they are fully prepared - which should include pointing out to an examiner that their licence has expired. Trying to deflect and transfer this responsibility to instructors or examiners by lawyers in post accident court cases is becoming an increasingly worrying trend.
Several instructors and examiners have recently found themselves up in court on recently trying to justify how they conducted a particular flight, often several years before. The real responsibility generally resides with the PIC at the time of the accident.
The whole nanny state mentality that says "if I cock up, it must be somebody else's fault" is creeping into our society to an alarming degree. Flying can be a potentially hazardous pursuit - like many other activities that involve a degree of risk - it is that risk which makes it fun. If you don't want to accept the risks - then don't do it! And if it goes wrong on you, unlucky but more often than not, there is a substantial element of contributory negligence/poor judgement on the part of the PIC.
Most examiners and instructors I know take their responsibilities very seriously but they cannot cover every single combination of circumstances that might arise in a pilot's future flying. Once a pilot takes on the command of an aircraft, it is his or her responsibility and no-one else's.
I do not know the actual detail of this accident, only what has been reported. It would appear that there was a degree of poor airmanship and decision making. Whether or not an examiner had checked the expiry date on a licence several months before made no difference to the outcome.
It is tragic when there is any loss of life, particularly when it may have been avoidable. Somehow trying to make it the fault of an instructor or examiner is cynical, inequitable and will lead to people leaving the profession as the risks are simply not worth the reward.