Maybe he didn't want her to have his number on her personal cell, but decided after the photo shoot, it was not really a big deal to him, so he didn't bother to block that last call? I am just not seeing it as a huge issue. Some may see it as, he didn't bother blocking that last call, cause he knew she was dead, and made the last call trying to locate her phone (or whatever), and didn't need to block it, at that point.
But if he was all that crafty, why would he want to leave a record of that last call? Why not just look for the darn phone, it couldn't have *gone* that far* ( just thinking out loud).
I agree this keep going around in circles. It's brought up a lot, by the He's Guilty-ers...The significance is just lost on me.