Well, folks, I've loved all your stories, but something that happened just yesterday takes the cake. But no, it's not my lab PARTNER, it's my lab DEMONSTRATOR.
I do the usual procedure, follow the instructions I was given to the letter. I make a plot on the computer and print it out, from which I derive a quantity. My quantity is not what theory predicted, so I ask the demonstrator what may have gone wrong. He tells me my plot is inaccurate, which makes perfect sense, as an ideal fit was made by the computer, which was designed to make the plot as accurate as possible. Nevertheless, he tells me to change my function, eventually forcing me to do so to make the "ideal graph", and surprise, surprise, the result of doing so makes a tangent from the data as big as the tangent from my query.
After something like half an hour trying to tell him that he's being ridiculous, he says something completely different. He tells me to measure the resistance of my entire circuit, piece by piece. Turns out it is such that there is no justifiable way to conduct the experiment anyway. No wonder my quantity was so different from prediction; the experiment was fundamentally flawed. But no, says the demonstrator, it was all my fault for reasons known only to him.
Me and my partner just left early after that, talking and laughing about how ludicrous lab is.