It seems odd to me that Billie was talking to DD at noon and SA already knew that Haylie was missing. Did she also talk to SA at noon?
Yes, that's what I think. The timeline is a royal mess - until you add in an assumed event of Shawn and Billie talking just before noon, and Shawn telling Billie that Hailey "has already left" (euphemistically that she, or her body, has been removed from the house), then everything that follows makes perfect sense.
- Shawn tells Billie that Hailey has been removed from the house.
- Shawn tells his mother Hailey is missing (at noon).
- Billie calls D and tells him to text MB to tell Hailey to come home.
- Billie sends D to Clint's house.
- Billie fails to contact Shawn and ask him if he's sure it was MB's house that Hailey was going to.
- Billie
tells Clint to call the PD and for
him to tell LE that Hailey is missing
before she speaks to them.
- Billie fails to call Shawn who she supposedly believes is nearby at work to give her a ride home.
- Billie fails to contact the love of her life to tell him her little girl is missing.
- Billie lies to Clint and tells him she's on her way to the PD to file a missing person report.
- Billie instead goes home and other places before going to the PD. (Was she checking for or removing something from the home before going to the PD?)
- Billie reports Hailey's time gone missing as 1pm.
- Billie and Shawn avoid calling each other through all this time.
There's lots more. That's just what I can think of from the timeline off the top of my head.