He called it a solvent so I sadly can't confirm wether he made a mistake or really did use a solvent. I also wasnt at a point where I questionned everything since I did not have the knowledge I have today and did not question the integrity of my coating back then as I do today.
It's a a damn shame indeed, specially since I did not think about it twice for I felt this was the best route for protecting my first brand new car ever.
No he did not use MDR while they tried to decon it, they just used Ferrex and a microfiber towels, although I did tell them I had used a claymit a day before so there was no point in adding it to the mix.
I did just fully decon my car 2 days ago although and did try MDR ;
Used Optimum CarWash in a foam canon as prewash
then washed the crash using Carpro Reset + a little bit of ONR
then proceeded to ferrex entire car while rubbing it with a microfiber towel
then used a claymit + ONR as the lubricating agent
then finally used MDR as a final step
then topped the car with Opti-Seal
MDR sadly did not do any miracles, everything behaves exactly as it did in the videos I had initially taken (Which is almost a year ago at this point)
The detailler has agreed to redo the coating on the horizontal surfaces (Hood, Top of car, top of trunk) but not the rest, which is essentially why I went to create this topic for I felt nothing looked right on that car, and while reddit people are not right about everything, nobody argued that the coating displayed adequate behavior.
My last car (a 2009 impreza) which I gave to my mother and proceeded to coat myself using Optimum gloss coat, beeds and sheets more than my WRX which gets far more maintenance as my mother washes it like twice a year.
For the first time since I've had the car I feel like a have a working coating, but that is because I have for the first time applied Opti-seal to it and it makes a night and day difference compared to how my coating by itself behaves.
Thanks for the replies, it's much appreciated!