From what I can determine, the authoritative version was always the one with the later timestamp. This might have worked at least in theory, however there were always issues.
The foremost issue was that the timeserver was virtualized, and drifted to an unbelievable degree. This issue was compounded by the fact that we used citrix virtual machines for some applications, and our local desktops for other applications.
The latter issue wasn't a problem until they moved the citrix servers from an on-site server room to cloud provider about 40 miles away. (I think this is when the timeserver became virtualized as well) At that point the latency between the citrix sessions and the local desktops was such that I could create a document on the file share, edit it on my local desktop, close it, save it, and then open it on the remote desktop and it would lock the replication from my computer and lose all my work.
My department managed to wipe out the changes every other department had made to the yearly budget workbook because of this interaction. Of course part of the issue was using Excel as a shared document, but that issue was hugely compounded by the fact that our network infrastructure was bananas.
For instance, building access databases using the Microsoft recommended separate front-end/back-end files, with each individual user having their own front-end file actually managed to make the issue occur more frequently. If you used a single access database file on a shared drive the issue was substantially less likely to occur. I can only imagine this is because the dedupe was postponed until everyone was done using the file, and the file was more likely to substantially change in size when multiple people were using it.
The IT director had an incredibly fragile ego, and he attacked anyone who challenged him in any way. He hired a truck driver (with absolutely no IT experience) to work the IT help desk, which I assume was because he wanted a sycophant. He reported me to HR any time I did anything he didn't understand or which perceived to be a challenge of his power. He reported me to HR for using open-source software, with a description of open source software that made it sound like Wikipedia meets programming, and only used by hackers. He also reported me to HR after he heard I called our IT situation Kafkaesque.
As far as nightmares go, that might have been my favorite, because my defense was literally "it is Kafkaesque, and I can prove it." I managed to successfully convince HR that the IT situation was Kafkaesque using examples from Kafka's work, whose response was "well there isn't anything we can do about it, but you aren't wrong."
The sensible thing would have been to leave as soon as possible, but I really liked the field I was in, which was kind of specialized. Looking back I stayed way too long.