We only know what we can glean from the limited evidence. We have the phone records. We have Rachel's testimony. We know she tried to call back at 7:17:30 or thereabouts. We know the first 9:11 call happened very soon afterwards. We have witnesses who put the times close to there.
Look, I'm not saying that it makes a hell of a lot of difference either way, but you simply can not use Martin's cell phone records to determine the moment of the confrontation, because we have no idea how it was ended on Martin's end... All we know is, Martin himself didn't do it. The call could have been cut off when she heard the "wet grass" sound, or it could have lost it's audio capability or malfunctioned in the scuffle, and remained active for who knows how long after the confrontation, depending on the exact time the confrontation took place... Which unfortunately, we can't nail down precisely...
The closest we can get with any certainty, is Jenna's 911 call and her estimation on the time that elapsed from deciding to call 911, to when she connected with them. She says that she heard the verbal confrontation at the "T" and almost immediately after, she heard their feet scuffling toward her patio. That's when she decided to call 911, so I'm thinking no more than maybe 5 seconds after the verbal confrontation, she decided to call 911... Evidently there was so issues with her phones or something, I never heard what it was, but at any rate, she estimates that from the time she decided to call 911, until the operator answered her call, was 30 seconds.
Her call was answered at 7:16:11 and if you subtract the 35 seconds, the confrontation has an approximate start time of 7:15:36.
I realize your case takes at least a half minute time hit this way, but at least we know it's reasonably accurate and still leaves Zimmerman with plenty of time he still has to account for . Besides, even if you assume Martin's call got cut off at exactly 7:16 pm on the nose, according to Jenna's testimony, there's no way she could have connected with the 911 operator that fast.
We're trying to figure out what happened, right? And part of that is figuring out where people were at given times. Zimmerman has no account of this missing time and in fact lied about it several times. It's logical to assume that he continued his search and covered it up. It doesn't go to self-defense per se, but it goes to his character and credibility. We're testing his story, and even you agree that this part of it doesn't add up. Let's see what we get this coming week.
Believe me, personally there's nothing I want more than to know the truth of exactly what happened that night second by second, and detail for detail... With all the time I've spent pouring over the evidence and debating this thing, I think I deserve to know the truth... Even so, there is something I deem more important than knowing everything that took place that night, and that is that justice gets served in this case... I don't care if Zimmerman lied, Rachel lied and every single eye witness fabricated their testimony, as long as in the end the jury doesn't allow a murderer to go free, or rob an innocent man of his freedom.
As for the missing time, I'd like to know one way or the other where it went. If he did spend that time looking around and hoping he might see Martin, it wouldn't surprise me at all. He could have just hung out on RVC for a few minutes hoping he might spot Martin going out the back gate. I will say this though... Unless there is some simple, perfectly logical explanation that we've all overlooked or were unaware of that resolves the missing time, Zimmerman will take a credibility hit with the jury whether he testifies or not. But like I said before, as long as that missing time can't be directly tied to activity that would take away his ability to legally claim he acted in self defense, it just doesn't hold a lot of meaning to me one way or the other.