tldr:
first year in college we programmed 24 hrs straight to fix somebody's mess before the deadline. Decided not to screw him over, instead he claimed to have done everything and we failed the assignment.

Long version:
var group= new[]{"Mike", "Gavin", "Gus", "I", "Ben" };
var client = "Jack"';

First year of college we had an assignment to make a web program for somebody.
Ben wanted to join our group and he already knew a client so we let him join.

After joining Ben wanted to be project lead, but we already decided Mike based on his experience.
Ben claimed to be much better in every way than Mike at and kept coming with stuff the following weeks why we should make him project lead. He kept pointing out when Mike did something wrong and he even came with an audio file where he clearly made jack say that he wanted Ben to be project lead .
After that we were all a bit pissed and told him that he should get it in his head that he was not going to be project lead and just start working on his part of the assignment.

We also found out that Ben was a documentation addict, what we could write in a small paragraph, he wrote a whole page about it. No joke, I rewrote a page of his in 5-6 rows with the same information in it.
No problem you thing, wrong! Because of this he kept bothering us arguing and claiming that our documentation was wrong because it was to short.

In the week of the deadline we asked Ben if he was also done, and told us that he was done for a while now.

The day before the deadline we came to school thinking we only had to do some merging and finishing up documentation.
Then we found out that Ben has almost nothing, and what he had the IDE was screaming that it was incorrect, spaces in Id's and css class names for instance. A really good programmer, my ass!
We were so pissed off at this point, but we had 24 hrs and needed to come up with a plan to fix it.

We decided that Mike and I were going to fix Ben his shit in the coming 24 hrs and Ben was going to make our last bit of documentation because we would not have the time for that, Especially if we had to argue with him like we had to do for each bit of documentation. Gus did not have time and Gavin could not program on his own yet, he wanted to help, but helping him help us would cost more time than we had.

We all went home after that and Mike and I started to program 24 hours straight while in a Skype call, making what Ben had 2 months for. Shortly before the deadline Mike looked at our finishing up documentation received from Ben and told me it was "Okay" and zipped everything up and uploaded it to school with a few minutes to spare.

After that we thought everything was good, we made Ben's part work and delivered it in time. We also decided not to throw Ben under the bus, because this would hurt all our grades because we did not work good as a group since we should have noticed it earlier.

A few weeks go by till the assessment.
The assessment start with asking if we want individual grades or as a group when you all think you did equal amount. We choose as a group, because if we chose individual not only Ben but also Gavin would get a lower grade and we did not think that was fair because he tried so hard.

We demo the product and the teachers are positive. When the teachers start about the documentation, the first thing they tell is that they found something interesting in the documentation, and they read it to us:

"I, Ben, have made all the documentation because my group did not want to."

That was so far from the truth, we all did make our documentation about the parts we made. Yes he did do overall a little bit more because every single bit of documentation we had to argue with him, so every time he volunteers to make it, we would all agree. And he made Mike's and i's last bit of documentation.

Telling the teachers on that point would not have mattered, it would only have hurt is in another way, so we did not and all failed the assignment. And we all felt like to strangle him.
This is now a few years back, but i still want too.