I don't know why this whole non-issue has become such an issue for me, but I've been following this way too closely. Here is the evidence I know of:
Obama never said cops acted stupidly, period end of sentence. Words matter. He said "The Cambridge police acted stupidly in arresting somebody when there was already proof that they were in their own home."
Sgt. Crowley gave an interview on the radio. You can listen to it here.
Prof. Gates gave an interview on the radio. You can listen to it here, after a click or two.
The police report is here.
And a story from The New York Times dated July 29, 2009 on this subject is here.
That's basically my data. Below the fold is my analysis.
Sgt. Crowley likely lied. Police lie all the time, like this story from Florida today titled Crooked Cops Caught Plotting To Frame Motorist. Lucia Whalen says that Crowley lied. Prof. Gates says Crowley lied. So many facts are in dispute, still, like was there a "yo mama" statement by Gates, did he show his Harvard ID only or that plus his drivers license, etc. But it doesn't make a damn bit of difference.
The law regarding disorderly conduct in Massachusetts makes Gates's behavior perfectly acceptable. Don't believe me? Read What is 'disorderly conduct' in Massachusetts?.
So there are two possible scenarios here, as I understand it. If Crowley's story as written in the police report is accurate to the word, he behaved stupidly. If Crowley's story as written in the police report contains factual errors, he lied, and thus acted stupidly and lied.
That's all.