This has been posted to the Dallas forum already. My read of the "story" on that site is that the reporter does not know how to write a news story and the person making the complaint is unintelligible and vulgar.
The issue seems to revolve around a synchronized clock system where the "lead clock" is called "master" and the others are called "slaves". That's standard terminology in one-to-many synchronized devices, but the terms certainly have sociopolitical ramifications in today's environment.
I've even seen strong criticism of the terms "male" and "female" in plugs, connectors and the like. Some, unfamiliar with the nature of even such a low tech item as a plug and socket, find this offensive.
My suspicion is that the historic use of "slave and master" in synchronized devices was unknown to some, and it caused a response that was unwarranted by facts. Hopefully, we will get a better written report on this incident that includes the standard journalistic "who, what, where, when and why", most of which was omitted from the story.