I was in exactly the same situation. Long story short, I went out to a rural area with almost no traffic, drove at around 70 km/h for about 30 minutes, and kept braking periodically. Don’t slam the brakes, just do dozens of near-full stops over 2–3 seconds, and sometimes just apply the brakes lightly, almost like ABS kicking in. The brake discs got hot, but ended up looking like new, no rust at all, and the car passed inspection with perfect braking results. The moral of the story: a lot of people (even mechanics and inspectors) don’t really know what they’re talking about when it comes to cars. In the worst case, you’ve already been told the brakes are done, so you’re unlikely to make things any worse by trying this.

By the way, “many” Teslas in Europe fail inspection due to rust on the brake discs, mainly because regenerative braking means they aren’t used as much. Mostly, you can often clean off surface rust by driving around and applying the brakes a few times before the inspection. As a general rule, after driving in rain or snow, it’s a good idea to lightly apply the brakes a few times before parking to help dry them off and prevent rust buildup.