Do you mean "ridiculous" as in 1970 Kent State ridiculous, where The National Guard shot and killed four students?
Or do you mean "ridiculous" as in something like this:
source
I don't know what the future holds, but you can bet your ass if it is for the military to do what they are training them to do right now, it will be done. Maybe not by all of them, but by many.
Not sure how much you know about the history of battle, but starting back in the Civil War days, it was found that many muskets were double loaded. That means they were not fired, but loaded again. The point is, they would not fire on each other. Off the top of my head I don't remember the figure, but it was a staggering number, something like 40% would not shoot. Through the wars the military notices this problem and through "repetitive training" they were able to get their men to shoot around 95% of the time in Vietnam. Each war prior to Vietnam was better than the last, as they improved their training.
What does that mean? That means through repetitive training the military has learned how to train their soldiers to shoot and kill without giving it a whole lot of thought. Don't think for a second if that order is ever given (I don't personally think it will be), that most of them won't react simply due to their training. When the bells ring, the dogs will come running. Hesitation will be trained out of most of them, if it hasn't been already. That is the job of the military, as soldiers are of no use if they can not follow orders and the chain of command.