The reason for the change in tone is that Gates has talked to his lawyers and very likely has learned that he has potentially very serious legal exposure on his hands.
The legal problem for Gates occurred when he went outside the house and yelled to the gathering crowd words to the effect that Crowley was a racist cop.
If Crowley is NOT in fact a racist cop, then Gates has slandered Crowley.
It would not be a problem for Gates if he said that only in the presence of Crowley, but when he said that to the onlookers, he "published" the statement within the meaning of defamation law.
Gates would not be exposed if Crowley is in fact a racist cop, because truth is a defense to a slander charge.
Gates could always claim that Crowley called him the "n" word in the house, or some such thing.
However, it now appears that there are police audio recordings from Crowley's open mike, which could establish just what was said inside the house. Outside the house, there are witnesses as to what was said.
Liberals often think they can say any nasty lies they like about someone, because of the "actual malice" standard under defamation law - the slandered party has to prove the speaker harbored "actual malice" in his heart to recover.
Gates may not have realized that Sgt Crowley does not come under the "actual malice" standard because Crowley is not a public figure or a public official.
You might say, wait, isn't a police officer a public official? No, say, the courts, a public official generally is meant to include policy-making officials - not a rank and file government employee like a patrol officer.
So if police recordings exist to prove the content of the conversation inside the house, and if Crowley did not say or do anything to evidence that he is a racist, then Gates is in deep sh!t, legally speaking, because he has slandered Crowley.
Furthermore, this is probably defamation per se, which means that Crowley does not have to prove actual damages to be able to maintain a lawsuit against Gates.
However, I think a jury would find substantial damages against Gates given that Crowley appears to have an existing reputation as the opposite of a racist cop, in fact teaching police cadets about the dangers of racial profiling and having attempted to save the life of a prominent black basketball player, Reggie Lewis.
So Gates has some serious making nice to do with Crowley if he wants to avoid a possible large legal judgment against him.
By the way, Crowley needs to be careful about how he meets with Gates and Obama.
If Crowley has a conversation alone with only Obama and Gates, they can claim Crowley said something that betrayed a racist mindset or that he said something that could be interpreted as admitting (such as an expression of regret or apology) that what he did or said to Gates at the time of arrest could be considered racist.
Crowley needs to have an objective witness present at all times during the meeting with Gates and Obama, and Crowley needs to talk to his lawyer before the meeting in order to be absolutely clear on what not to say.