He thinks (and acts) that you can self appoint yourself as police, when he doesn't even know the laws himself - in doing this, he's endangering his life and others - he acts like this on the road, I'd hate to see him in the stores.
What an utter, utter prick.
If you have passed the signs yourselves seeing them show the emtpy lanes still marked as closed, and soon after sees cars starting to drive in them, it would be pretty logical to do some reasoning with yourself and understand that they just might have seen something completely different on the signs after you passed it. So utterly, mindboggingly stupid. Even if the lanes were in fact still closed, I know of no country where a civilian has any right to do this. I've understood this isn't the case in the UK either.
If you check the MOT history you can see on-going tyre issues, so he's probably just going slow to not have a crash lol