Caught it on Saturday too – made good TV, but obviously filmed over several weeks if not months, probably hence the continuity errors – like the first tentative foray into the tunnel immediatly after it had been pumped out – with acro props in place and partly concealed halogen flood lights fixed to the walls! Best way is to just enjoy it and not get too envious at not being involved in such digs! 😀 Bet they were a bit miffed at finding that it had not been completed, as these bunkers normally reveal a treasure trove of artefacts – I have seen more than they found on an afternoon’s walk in the Argonne!
Remember finding one of those big pumps several years ago at a road works site near Ypres – the workmen said take it, but the wife said NO! 🙁
It was interesting though as my Grandfather was a tunneller in Flanders, but typical Time Team, nearly, but not quite, a bit like the Reedham Marshes B17 programme which is on satellite endlessly.
I too have never seen the Invaders in the Marsh programme which is more disappointing as it was in the area I hail from originally, havent found it on the net or anywhere !