The guy who's sitting with you should be predisposed to pass you on to the field. If he doesn't, it's because you did something wrong AND your instructors tell him, "Yeah, that's consistent with where he's been the whole time."You have 9 weeks at the Academy to pass 2 pass/fail exams (well, did until they changed it to the new points-based PV). You get months to years of training in the field, specialized to your facility with your traffic and there's no "fail this session and you're done" bullshit to contend with.
The PV system just isn't set up well. Some guy who sits with you for one run can't possibly know what kind of controller you'd make in the field. I've been working with the same trainers for 6 months...I've had the same supervisor, and I'll be checked out within another month or 2. My trainers know it, my supervisor knows it, and I know it. Is it possible that I might have a crappy skills check? Maybe. Then I get another 10 hours of training and we run it again, because my supe knows how I work and maybe I just wasn't as efficient as I could have been because I was tired or something. It's not some random guy who comes in from some random facility and doesn't know me just throws on a headset and says "Ok bro let's see how you do, you don't run this shit like I want you to and I'm recommending termination of training." That's not how the real world works, and it's why the Academy is a shitty screen.
As for the idea that there are no make-or-break sessions after the Academy, I promise you that there are. If you are a trainee who has struggled to separate airplanes the entire time, then your last 40 hours/3 weeks of training are what I'm using to determine whether I can recommend you for certification. You sound like you've done well the whole time, so an A1 for you might get written off by your trainers as one bad day, especially if you don't need their help to get out of it. If you had done poorly up to that point, then that A1 would be a sign that you still don't get it, and a TRB is required.