There are numerous things that are being overlooked, most importantly (1) the fact that officials do not make rules; they only enforce them, (2) the interpretation of rules is not determined by the officials; it is determined by the meet director/games committee, and (3) the full process for a DQ.
1) Officials do not have any say in the writing of the rules and it is not their job to enforce/not enforce only those that they agree with. Getting upset with an official for enforcing a rule is like getting upset with a police officer for pulling you over for going over the speed limit. The officer did not determine the speed limit; someone above his level did. The officer is required to enforce the rule, even if he disagrees with it. If he doesn't then he is neglecting his duty and has no business serving as a police officer. Same goes for officials. In fact, this is specifically addressed in the NFHS Rules Book, Rule 3-2: "The meet referee, other meet officials, or the jury of appeals shall not set aside any rule." There are many rules that a lot of us do not agree with but we enforce them anyway because we are required to. A perfect example is the elimination of five-alive for vertical jumps in the NCAA. I love five-alive, as do nearly every collegiate pole vaulter I have ever worked with. If I have a group of 45 vaulters and every one of them and their coaches wanted me to do five-alive, I still cannot do it, because the Rules Book was amended a couple years ago and specifically states that the use of five-alive is "not allowed." If I don't conduct the competition according to the rules, I risk causing vaulters' marks to not be accepted by the NCAA. And don't get me started on some of the uniform rules. I hate them, but I enforce them because I do not have the authority to not enforce them. Any official who selectively decides to only enforce rules that he/she agrees needs to leave the job.
2) Some rules are black and white and some are gray; Rule 4-6 is very gray and open to interpretation. What exactly is "unsporting" behavior and "unacceptable" behavior? Some examples are given in the rules themselves, but the possible situations are almost limitless. How this rule is applied is up to the games committee or meet director. If the meet director tells the officials, "There is zero tolerance - any celebration before crossing the finish line is 'unacceptable behavior'," then this is how the officials will enforce it. According to another poster who was supposedly at the coaches meeting, this is what they were told. The official was simple doing her job by enforcing the rule as interpreted by the meet director. If you have a beef with the way the rule was enforced, you need to take that up with the director.
3) Contrary to what a lot of you who have never officiated think, NO umpire disqualifies a runner; only the referee can do this. The umpire who raised the yellow flag did NOT disqualify the runner. The process is straight forward - the umpire reports what he saw to the head umpire, who then presents this information to the referee. The referee then makes a decision based on this report. But wait! The process is not over. Because then the inevitable appeal will be filed, and not official, not even the referee, has any part of this process. The Jury of Appeals, which at HS state meets usually consists of the meet director, a representative from the state association, maybe a highly respected retired coach, etc., addresses the appeal and has the option to concur with the referee's decision or overturn it. In the case of this relay, the umpire, referee, and the jury of appeals all agreed with the decision to disqualify the runner. But, like the police officer who pulls you over, the only person who gets targeted is the umpire doing her assigned duty.
Despite what you read online, the warning had absolutely nothing to do with the DQ. The NFHS Case Book specifically states, "There is no provision that a warning must precede a disqualification." The fact that he was given a warning earlier and still did what he did just makes it look worse for the athlete. It borders on "willful failure to follow the directions of a meet official" - which is word for word from the definition of "unacceptable behavior."
And to those who keep complaining about the "mean old guys" who are ruining track and field, I have a simple question. Where are you? Why don't I see you on the track? I've been doing this for many years at the college and high school levels and all I see is the group of us getting older and older. Where is the young blood to replace us? It's time you get off your butts, get out of the stands, and go work some 12-hour days under the hot sun for a cold sandwich, a warm drink, a bag of chips, and maybe the occasional "thank you" from an athlete or coach. I would love to sit in the stands for a change and watch the races, but instead I miss almost all of them because I am too busy running my event. I would love to see some younger blood in the officials' room. What is going to happen when all of us are gone? Are you going to volunteer to be one of those "mean old men" or are you going to be fine with nobody officiating at meets at all? Maybe T&F can become like a pick-up basketball game, where players call their own fouls. That doesn't sound like it would result in any controversies.