Archaeologist sells Find?

On Ebay we have another example that appears to be a case of a British archaeologist trading in artefacts: 'Early Neolithic flint tool fabricator from West Kennet, Avebury' (Item specifics Provenance: Ownership History Available Type: Fabricator Colour: White Material: flint). Description by drdaz (1072):

Unique opportunity to purchase an Early Neolithic Flint Fabricator tool from West Kennett, Avebury. At the time I was a postgraduate archaeology student attached to The Windmill study in 1992. I was asked to do a transect study of the the area adjacent to the long barrow tomb. The flint tool is from my own collection from that time. As the Avebury has now World Heritage status these flint are increasingly rare. The implement is approx 6cm by 3cm, showing multiple blind percussion fractures on one end, and bifaceted opposite pole. There is evidence of reworking of the lateral edge. The flint has the usual white patina of an object of this age and of this area. It is coded WKA14.

Anything goes in British archaeology these days and it seems this goes back even beyond the beginning of the PAS. Drdaz sells mainly general tat and collectables, but among them in the feedback one can see something called a "British Neolithic / Mesolithic Flint Hand Axe West Kennet, Wiltshire. UK (#121924423467)". We cannot know what that really was, but in this case one archaeologist's 'fabricator' is another archaeologist's broken pebble. Even so, this raises a number of ethical issues - including how Drdaz was collecting material while part of a project. I am going to charitably assume that the guy was surveying, picking up flints and stuff and that at the end of the day the finds supervisor rejected this lump of crud as an artefact and "Dr Daz" refused to accept that verdict and asked if he could take it, and for 27 years has cherished the notion that the 'ignorant chumps' back at the project did not recognize their genius and this stone was for them part of the proof of that. So why are they selling it?