This happened with one of our senior profs during the first year of my college. I wouldn't call him a dev if my life depended on calling him a dev but regardless, I narrate the story here.

We were "taught" C++ by some really dumb professors during our first year of college and it was mandatory that everyone cleared the subject regardless of what field of engineering the students chose. Having already done 2 years of C++, it was quite a breeze for me. But during the final lab exam, one of my friends requested my help in solving the quite tough question (for those beginners). Thinking the exam and teaching was unfair, I stupidly wrote the answer on a piece of paper and passed it to him. One of our teachers, who had seen him ask me, was lying low waiting to catch me in the act and she swooped in and busted our asses kicking us out of the exam hall and sending us to the HoDs office like some prize from her war against academic corruption.
In the end, I failed the exam for cheating and had to redo (not only the exam but the entire lab course).

When I returned to college during the summer vacations to redo the course, I first met the antagonist of our story. Having a huge head that looked like a deformed watermelon and an ego the size of a building, he assaulted us first with a verbal diarrhoea of his achievements as a CS professor. I quickly realised that I was in a class of people who had failed to grasp how to make a program that printed "Hello World". To make things shorter, every question the prof gave us, I managed to solve in a mere matter of minutes, several better than his own solutions. Not having expected a student who knew his shit, he was determined to play me down. He hurled tougher question at me and I knocked them over his enormous head piercing his ego. He asked me such questions as how to reverse 1000 and get 0001 and wasn't satisfied with the several ways I gave because none of it were what he had in mind (which turned out to be storing them in a fucking array and printing them in reverse. That's printing not reversing you dung beetle). I kept my calm throughout but on the day of the final exam, he set quite a tough paper for a class of people who had already failed once. To his utter shock and dismay, I aced that too and I produced flawless code. This man who has an MTech from one of the most reputed colleges of my country then proceeded to tell me that he had to cut my marks because I had used more than one function when the question had asked for one function ( it never said only one). I lost my shit and pointed out that since I was the programmer, it was my wish how I coded. I also explained to him how repeating code is a bad practice and one should use functions to reduce redundancy and keep the code clean. Nevertheless, he lost his shit and he threatened me with consequences as apparently "I didn't know who I was messing with". I handed over the paper and stormed out of the class (though he called me back and tried to argue more with me. I apologized for losing my shit and left when he was done talking). I ended up getting a 'C'. Totally worth it.