I think that 'rabbit in headlights' thing has a lot to do with it. It's just after the first 100 miles, you'd have think something would have dawned...

When it happened to me, it was only a FIAT 124 and I carried on driving until the brakes faded. But I was able to jiggle the linkage & release the offending carb. cam.

IIRC, there was a round bobbin thing in the middle of the V12 connected to long pushrods and the cable could jump off it, if loose, and the vacuum pulled both butterflies wide open...

 

Don't modern cars have a fuel cut off activated by a front impact. Plenty of immigrants around Calais so I'm sure they could have found a gang willing to drive in front of matey and slam the brakes on. Happy days all round. Matey's Renault will slow down enough for him to drive into a ditch and the gang get a pay out for whiplash. Although I bet that doesn't happen in France, only here.

 

Even if the closing impact is only 15 mph, it takes a huuuuge amount of cajones to drive into Norbert Dentressangle's rear under-run bumper.

But ten sets of disk brakes, and exhaust brake & possibly a hydraulic retarder will outvote any struggle buggy's engine, without breaking a sweat.

 

Happened to me in a VW truck once. I had time to drive round a bit of traffic while thinking then got onto the hard shoulder and switched her off, clutch in, neutral, coast/brake without servo

Scary at the time.

But then I'm not French

 

Reality check :
"A Renault technician had been on the phone with police throughout the chase trying to help but couldn't come up with a solution."

 

Can one gallic shrug down the 'phone?

Client of mine had to park a 7.5 tonner into a wall, when the brakes failed (hydraulic leaked invisibly into the air over bit). Fortunately it was at traffic speeds and they (Ivecos) are quite strong.