Side Panels of DOOM!!!

Yeah, so I work at Earhart Dining Hall. I am a student associate. I usually work cleanup shift due to my abundance of 4:30-5:20 classes *cough cough* Anyway... I have worked there since the beginning of the year and I usually end up shutting down the salad bar. Now, when you shut down salad bar, you have to take out panels on the bottom and the sides. On salad bar there are two rectangular wells and the long sides have panels that have to go in a certain way. In each well, one of the long side panels has six rows of slits for ventilation and the other side has two rows of slits. When I first trained during BGR week I was told that each well had to have a six and a two, but it didn't matter which side they went on. Today, I got told, after I had finished putting everything back together and had started wiping down tables, that the six slit side panel has to go on the left side of the bar. So I had to take the entire bar back apart, because of course the side panels go on first, and switch the panels. I was rather annoyed because this was the first time I had heard of this and I hate looking dumb in front of my employers. To top it off, the supervisor who talked to me about it is not one of the ones who I generally interact with, so I feel like I have given a sub-par impression to him. Oh well, the other supervisors like me. ^_^