My theory:
Nate followed him and killed him and I don't think Annalise sent all those calls at the same exact time. I just think they showed it that way to throw viewers off. Asher was in on something because he hid Conner's phone at Michaela's place. Frank seem mentally broken and kind of proved that he's not as fearless as we thought when he didn't pull that fucking trigger for Annalise. He decided to stay for Bonnie. It's either Bonnie or Nate that played a part. Bonnie loves Annalise more than anyone on the show.
