I think the worst failure mode I've ever seen is one team that maintained a "git repository" for a collection of analysis scripts that was simply a directory on a shared drive. It was technically speaking initiated as a git repository, but practically speaking it wasn't used as one: rather, the directory contained zipped copies of the code timestamped with when they were modified. There were very few commits to be seen, and I honestly hesitated to try and branch from them in any meaningful way. Of course there was no command line interface or anything to be had, and the git GUI software they had available was muddled enough that it confused me. In this situation, yes, *technically* they were using git, but in any real sense this clearly wasn't the case.