This is getting silly. The case is applicable. Prof. Gates was making comments at the time to Crowley. The speech was protected by the First Amendment and your interpretation of the law is simply wrong.
There is a great deal of Massachusetts law on this topic and some of this law predates Houston v. Hill
http://www.reason.com/news/show/135084.html Even if we accept Crowley's version of events, the arrest was not justified (a conclusion reinforced by the city's decision to drop the charge). Let's say Gates did initially refuse to show his ID—an understandable response from an innocent man confronted by police in his own home. Let's say he immediately accused Crowley of racism and behaved in a "loud and tumultuous" fashion. So what? By Crowley's own account, he arrested Gates for dissing him. That's not a crime, or at least it shouldn't be.
In Massachusetts, as in many states, the definition of disorderly conduct is drawn from the American Law Institute's Model Penal Code. A person is considered disorderly if he "engages in fighting or threatening, violent or tumultuous behavior...with purpose to cause public inconvenience, annoyance or alarm" or "recklessly creates a risk thereof."
Crowley claims Gates recklessly created public alarm by haranguing him from the porch of his house, attracting a small crowd that included "at least seven unidentified passers-by" as well as several police officers. Yet it was Crowley who suggested that Gates follow him outside, thereby setting him up for the disorderly conduct charge.
It's hard to escape the conclusion that Crowley was angered and embarrassed by Gates' "outburst" and therefore sought to create a pretext for arresting him. "When he has the uniform on," a friend later told The New York Times, "Jim has an expectation of deference."
As the Massachusetts Appeals Court has noted, "the theory behind criminalizing disorderly conduct rests on the tendency of the actor's conduct to provoke violence in others."
See also
http://legalblogwatch.typepad.com/legal_blog_watch/2009/07/gates-gate-whats-the-law-say.html In a 1976 decision, Commonwealth v. Richards, 369 Mass. 443, the Supreme Judicial Court of Massachusetts held that the First Amendment prevents application of the disorderly conduct law to language and expressive conduct, even when it is offensive and abusive. The one exception would be language that falls outside the protection of the First Amendment, "fighting words which by their very utterance tend to incite an immediate breach of the peace."
See also
http://blog.masslive.com/thefray/2009/07/what_is_disorderly_conduct_in.html Arrest under Massachusetts "idle and disorderly person" statute was unlawful under Massachusetts law, where defendant was arrested for yelling, screaming, swearing and generally causing a disturbance but, though the yelling was undoubtedly loud enough to attract the attention of other guests in hotel, it did not rise to level of "riotous commotion" or "public nuisance." U.S. v. Pasqualino, D.Mass.1991, 768 F.Supp. 13....
Defendant who did not physically resist his arrest arising out of a domestic violence incident could not be convicted of disorderly conduct based solely on his loud and angry tirade, which included profanities, directed at police officers as he was being escorted to police cruiser, even if spectators gathered to watch defendant; defendant did not make any threats or engage in violence, and his speech did not constitute fighting words. Com. v. Mallahan (2008) 72 Mass.App.Ct. 1103, 889 N.E.2d 77, 2008 WL 2404550....
Defendant's conduct, namely, flailing his arms and shouting at police, victim of recent assault, or both, after being told to leave area by police, did not amount to "violent or tumultuous behavior" within scope of disorderly conduct statute, absent any claim that defendant's protestations constituted threat of violence, or any evidence that defendant's flailing arms were anything but physical manifestation of his agitation or that noise and commotion caused by defendant's behavior was extreme. Com. v. Lopiano (2004) 805 N.E.2d 522, 60 Mass.App.Ct. 723.
The First Amendment has limited the Massachusetts disorderly conduct law to situations where there is a risk of violence i.e., fighting words. You may not like the law but the law is clear here