In November 2012, an anonymous man (apparently not a metal detectorist) found an old coin in the silt of a river at Saltford "near Bath" in Somerset (FASAM-73C2A). The exact findspot, associations and context have not been revealed, but despite this, the British newspapers are getting excited about this Carthaginian piece (struck at one of several mints in the Punic Empire, including Carthage and cities on Sardinia, 300-264 BC) being "certainly one of the earliest coins found in Britain". Archaeologists are freely narrativising it as evidence of "trade with the Mediterranean, probably via Gaul" and linked (of course) to the tin trade.
The news items do not mention the issue of interpreting a contextless find in such a manner. Not a word there showing that the Finder-partner PAS has been achieving much success for seventeen million quid in “raising awareness among the public of the educational value of archaeological finds in their context”.
Neither does anyone pose the question, let alone answer it for the curious public, of why if someone was setting off on a voyage to a part of the world with no monetary economy (which a trader would know about) they took cruddy coins and not glass beads or bike spanners with them, and what the natives would do with a cruddy coin or bike spanners when they had no bikes.
Never of course in the entire history of Bath, Regency town par excellence, did there ever live a single collector or Grand Tour participant in it, no inhabitant of the town, or fashionable country residences around ever have even the smallest amateur cabinet of curiosities. No 1950s grammar schoolboy anywhere within fifty miles of Bath ever had a coin collection. Ever. So it is perfectly impossible that a stray ancient coin could have wandered into a field, or into the river from one such modern accumulation. Or at least of there is, the archaeologists are not saying. It makes a far more "interesting" story not to think too hard about the taphonomy of the find.
We often hear - particularly loudly from the UK - about "public archaeology", archaeologists doing archaeology "for the public", the public being involved in archaeology (it's what they set up the PAS for). Yet where is the evidence that British archaeologists are indeed giving their public something that is real meaty, recognizable, archaeology and not pre-digested pap? Because the BBC repeating archaeological (numismatic) glee over an out-of-place artefact in the mud and the trite uncontrolled 'dot-distribution-and-looks-like' interpretation placed on it really seems little better than pap.
BBC 'Ancient coin suggests early activity on Bristol Channel' 14 April 2015.