I might be barking up the wrong tree but both of my last two cars appear to have suffered from glazing of the friction plate.

I say 'appear' because neither was stripped down. My diesel CRV clutch started to slip at about 60,000 miles. I am very easy on clutches and have literally never had to replace one in 40 years of driving, so I couldn't believe it was worn out unless it was faulty. With nothing to lose I roasted the clutch and it was fine. I had to repeat the process once in the next 40,000 miles. I sold the car at 100,000 still on the same clutch with no sign of slip.

I have since had a similar experience with the Outlander, and have 'mended' that the same way.

What I'm speculating (and it is a thin hypothesis I know) is that your garage has noticed some slip, 'tested' it as you have done, and between you you have fixed it! I'm not particularly attached to that theory, as I don't really expect faults to mend themselves, but I'm struggling to find a better explanation for my own experiences.

I suppose it could have been contamination but if there was a fluid leak I wouldn't have expected the CRV clutch to be good 40,000 miles later. I have come to the conclusion that my driving style (I never hold a car on the clutch, and slip it as little as possible with the minimum of rpm), combined perhaps with modern non-asbestos materials and living in a flat area just polishes the clutch rather than wearing it away.

Of course both of these turbo diesels have (compared with the naturally aspirated petrol cars of old) enormous torque in the normal driving range. I do wonder if some of today's clutches are really man enough - the Outlander claims 380Nm of torque at 2000rpm; compare that with the 168Nm at 3500rpm of a 1991 Audi 2.0 petrol I had at one time, and I don't suppose the clutch is a lot bigger.

I'd be inclined to soldier on for a bit and see what happens, if you are confident it isn't slipping now. Just make sure your breakdown cover is current!