The oral went well, no problems. There was a miscommunication between myself and the check airman acting as PM. (Another one was actually giving the ride). The PM told me he was going to deactivate certain deice items, while leaving others still on. I was doing something else and he had the aircraft at the time. I looked up and acknowledged what he did. The CA in the back only heard part of this and thought that I had thoughtlessly left certain items on when they were not required anymore. He then gave me a failure where one of the abnormal checklist items specifically referenced the one piece of deice equipment that the PM had "forgotten" to turn off. We were going to be descending right back into icing, so when I got to the conditional statement in the checklist I interpreted it as "if you are using it" vs. "if it is required by conditions". The latter is what it actually said, so I can understand why the check airman wasn't satisfied with the procedure. What bothers me is that the PM told me he was leaving items on, and the check airman never heard him. (this part was clarified after I was failed) Despite what happened, I know there is no recourse or going back. I'm just wondering how this affects me going forward, and as per my original question, if a PC failure is seen as just as bad or worse than a pt91 bust to a potential employer.