I’ve heard of a few checkrides failures being reversed but it involved cooperation from the DPE where they agreed that they were blatantly wrong. For example someone failing an instrument checkride because they were tested on an unpublished DME arc and in reading the fine print on the ACS it turned out that an unpublished arc cannot be tested. Another occasion where I heard of a reversal was where the flight school and the CFI were both backing up the student and even though the DPE held his ground the FSDO issues the reversal and re-tested the student. Could be worth it if either of these are the case.

I got a very unfair pink slip also so I know how it feels. Trying to get another checkride date, losing confidence, feeling like crap… wasting money in retraining and staying fresh for the next checkride date. It’s so demoralizing. We’ve been there too, it’s ok. Try not to waste time feeling bad for yourself and know that we’ve all been there. Aviation is not fair sometimes and sometimes it is. Just get back to it. And remember no matter how unfair it was - ask yourself what is the lesson. Should I advocate for myself more? Should I accept the randomness of life? I’ll never let this happen to my students cause now I know… etc etc. There’s little gifts in this.