I think that ideally the prosecutor's objective here is not a "devastating" cross-examination but rather it is to lay the foundation for the cross-examination at trial or perhaps even to keep the defendant off the stand altogether.  This was a very rare opportunity that shouldn't have been wasted.

I can only really speak from the perspective of a former prosecutor and so my perception of how defendants prepare for trial is probably different from that of a defense lawyer who might find my perspective somewhat insulting.  Nevertheless, one of the reasons why prosecutors don't like cross-examining defendants (especially those with clean records) is that by the time they testify at trial the testimony of nearly all criminal defendants will conform remarkably closely to and avoid conflicting with the physical evidence or other highly credible prosecution testimony.  Many prosecutors attribute this phenomena to the fact that defendants testify after discovery and after the prosecution has put on its case.

Therefore the critical issue for the prosecutor in this type of situation would be to begin the narrow the defendant's opportunity to shape his testimony at trial so that it can accommodate irrefutable prosecution evidence.  Here, the prosecutor had the opportunity to take Zimmerman through the night's events step-by-step in a way that would have forced him to either testify truthfully or else take his best guess at how the physical evidence, etc is going to turn out before seeing any of the prosecution's cards.  If he says he remembers something vividly, he must continue to remember vividly.   If he can't remember something today, it will be much more difficult for him to suddenly claim a memory flash a year later at trial. And so forth. So the goal of the prosecutor (who does have some idea of where the physical evidence and eyewitness testimony is going) is to force the defendant to commit himself irretrievably to a version of events and to do so while blind to the state's evidence.  This is a part of doing the ground work for the cross at trial.  Hearings like this are sometimes where you get the "good stuff"----you get it the same way a bridge master makes his trumps good.  

What's more, such an opportunity can payoff in important ways.  For example, I think there is a high likelihood that Zimmerman will want or need to testify. The case is completely about him and there's nobody else who can tell his story for him (ironically enough since he's the only one left alive to tell the tale).  Plus, of course, we don't know what the physical evidence says and it may also be that the prosecution's case-in-chief is so strong that Zimmerman is practically compelled to testify. (If today is any indication that seems unlikely. But I'm really speaking hypothetically here).  And juries always like to hear a defendant testify, no matter what the judge instructs them.   There's also the fact that he's got a clean record and seems fairly intelligent and well spoken, all of which makes him difficult to cross.

What does this have to do with today's hearing?  His testimony today would have been set in stone. If it turns out to be sufficiently inconsistent with, say,  the physical evidence  he might not realistically be able to get on the stand because he can't maintain his prior testimony (because it's got too many holes in it or whatever) but because he's locked in under oath, he really can't take a different testimonial tack either.  In effect, this would be a powerful victory for the prosecution because his early testimony might ultimately have prevented him from personally persuading the jury of his innocence and then, too, juries do tend not to like it when defendants don't testify.  

The victim's sister "can't say".

One pastor "doesn't remember" the flyers or the meeting -- which was reported in local press, including quotes from Commissioner McCarty, who also doesn't recall the meeting and doesn't believe it could have taken place.

A second pastor doesn't recall ... or so we're assured by the first pastor ... and others are "skeptical".

And a Martin attorney writes that the letter is full of "blatant lies" -- but identifies no particular lies, much less any facts in rebuttal.

iow, in FL restraining orders can and are issued when there is no actual domestic violence, but merely the applicant's belief that there could be.