Yes the AAIB will search for his Log Book to determine experience. Unfortunately some Log Books are not found or the pilot has not filled it in for some time ( often years). In those cases the AAIB look for other ways to calculate experience ( employers records for instance) or sometimes they have to say in the final report ...unknown. Another good source is the pilots medical renewal forms which require hours to be filled in.

Licences have to be carried so are often lost in the accident. However holders of an AOC are required to keep records so the data is available. For
Private Pilots all that was required for revalidation in the past was a signature in the licence, but nowadays returns are required by the CAA.

Documents which are required to be carried are also sometimes lost, e.g C of A, C of R etc. However, all this data is held by the CAA/FAA and maintenance organisations, so can be easily retrieved.

Clare, my apologies for not agreeing with you but there are two topics of interest to me now.

1) The investigation, not the diligent safety investigation being undertaken by the AAIB, but what I assumed would be a concurrent investigation undertaken by the police. An investigation must now be undertaken because there will be an inquest but it seems that justice would have been well served by a swift operation to secure evidence or do the police assume that there are only transgressions of the ANO and can wait until the AAIB have completed their work?
2) I am interested in how many pilots consider the value of passengers for 3rd party liability before agreeing to transport them. There are several football companies who are looking for recompense, as well as people associated with the person who actually booked the flight as well as the family of the passenger. The trustees from Southern Aircraft Consultancy will have protected themselves by way of an Operator Agreement with somebody and no doubt have already passed the name of that person/organisation to the FAA. If the Insurance Policy of the Operator is in any way insufficient, then the Operator/estate of the pilot could be on the wrong end of a multi million pound legal action. Could the estate of the pilot be protected if an actual/implied contract of employment exists with the Operator?

just to add you would be well advised to keep a record of logs, licences and revalidations etc in a secure place where your next of kin know about it so that they can give it to the insurance company. Otherwise the question of your legality is another excuse to use to delay or deny any claim.