OK - by way of being devil's advocate, as requested by somebody last night, here is a question of logic:
If we are speculating that those text messages were sent by GBC in the morning as a means of contributing to an alibi and appearance of innocence, presumably he would be doing so fully aware that his phone would reveal those. That, in fact, it was the desired effect.
If that were the case, then wouldn't it be reasonable that he would also be aware that calls - Facetime or otherwise - made during the night would also be revealed?
Could it be feasible (I'm not saying "likely" - just feasible) that the calls in the middle of the night WERE something which they want to keep hidden, for whatever reason, but that the texts in the morning were genuine?
Just a devil's advocate question - not saying that IS the case, just one possible explanation. How do we reconcile the fact that there seem to have been shonky calls in the middle of the night, yet the texts in the morning are supposed to be calculated for his alibi knowing that the phone would tell all?