He didn't say autobahns are deristricted, he said it was on a derestricted autobahn.
Many are derestricted.
And although the advisory limit is 130 kmh, not a poncey 100kmh, exceeding it is NOT illegal. Sensibly the Germans allow discretion - you know, treating people like adults.
It certainly isn't "well over 5 years since it was introduced" either. The minibus I drove on the A1 in 2009 certainly wasn't equipped with an electronic member of the green party.