Project misfortune?

Here is the case.

X and Y, good friends, did a project together as their course's major project. In between the start and end of the project, the progress was not that good. Not that good as in the communication, the team work, etc...

Communication was not good because X did not stay at the lab with Y during the project development period. At first, however, X did move to the lab and work together but after some time, X decided not to continue to stay at the lab. X moved back to his/her house to continue with the project without stating a valid reason to Y.

Now time was near for a final demo of the project outcome to lecturers. Tensions felt as every single second ticked as it was also a test week. The night before the demo, X suddenly told Y that there were some changes to the project that need Y to also make his/her changes so as to match with X's modification. Y got suprised and tensed, and therefore X offered to prepare the changes for Y. Both stayed up until early morning that day and X finally passed the changes to Y and asked Y to make sure that the changes was OK. Y said that he/she will check later...

X actually has a test the next morning and therefore X continued with his/her study to prepare for the test with the remaining few hours. The next morning came and the test was actually before the demo. Therefore, X went for the test first but did badly. After the test, X went back to meet with Y for the demo. At that time, the lecturers were there and X found out that Y was panicking. When Y saw X, Y shouted at X asking why the changes did not work? Later, Y reverted back to his/her previous state, that is before the changes, and so the demo started. As expected, it was a bad demo despite an interesting project.

Until now, I still think back and try to figure out what has gone wrong with it, with the project? Unfortunately, I couldn't judge the case rationally... as there are just too much opinions inside my heads...

Period.