This is so frustrating. So, by 7:17 she was not responding. My theory, he said something about getting pot, she follows him out, and then leads the way but on Canary Loop, something happens and possibly a neighbor sights her car going out the unusual way. He had to have given her a ploy for some reason to "stop by his place." Once in his driveway, she is overtaken. That would be just about the time she no longer responds.
I really believe he was talking to her via DMs. His phone goes off just about the time that she leaves her home in Shipman.