Funnily enough, (given the trigger of this little spat) I once read a letter from Whitbread (once the UK distributors for Hoegaarden) responding to a landlord/CAMRA query asking was the beer real ale.
The letter confirmed that the beer was fermented with an ale yeast, that there was live yeast & a 2ndary fermentation occurring in the keg (though obviously dispense wasn't exactly "CAMRA kosher").
That said, the Amsterdam beer might even be properly considered "real ale", if the serving tanks are lined with plastic bags & dispense is aided by air pressure, if the beer is unfiltered, unpasteurised, with some carbonation gain in the serving tank + no extraneous gases coming into contact with the beer AFAICS, it all adds up to just about real ale!
In the recent-ish past these type of serving tanks have turned up in the UK - at CentreParcs in the 1990s (serving Foster's or something similar) & AFAIK all of the ZeroDegrees brewpub/restaurants have them, but happily serving unfiltered, unpasteurised, naturally carbonated beers. cheers MikeMcG