The timeline:
The pieces of the timeline being put together by posters in this thread are not all coming from the same source. A chunk of it is coming from the dad in the first interview he did on tv, in which he reiterated the story about planting flowers, going in the door, being seen by brothers going down to the basement, and then the basement door being unlocked.
The second piece of this timeline comes from a POLICE SCANNER. So someone called 911 and told a dispatcher that Summer was missing. This person could've been Candus or Don, we DO NOT KNOW. It also could've been a neighbor for all we know, or grandma. Then the dispatcher took that info and turned around and SUMMARIZED the situation to police, during which she said that Mom went for a walk. This was not a recording of what one parent told 911, it was literally a game of telephone in which the dispatcher turns around and recounts, in shorthand, to the police, what is happening and the reason for the dispatch. This to me is nothing. It is not real evidence of anything.
The third piece of this timeline comes from LESLIE, during her press conference on Thursday, in which she is asked the same question twice and is very obviously trying to only reiterate what has already been stated in previous statements to the public and not release new information. She REITERATES the story about planting flowers but when pressed, by two different reporters at two different moments, she again tries to summarize what happened and states that Summer was last seen "early afternoon" and the missing call to 911 came in around 6:30. Again, she is, in my opinion, VERY CLEARLY trying to avoid giving specifics here for her own reasons but when she resummarizes the situation, she uses a new phrase that sets the public off on a tizzy. I doubt that was her intention here. If you don't agree, please go back and actually watch the entire press conference from Thursday afternoon, in its full context, so you actually understand the circumstances in which Leslie used the phrase "early afternoon."
We are piecing info together from all these different sources and trying to make this mean that the timeline is muddled. Of course, it's muddled! It's all coming from different people, different contexts, etc. This would be a red flag if these were ALL interviews with the same parent over the course of several days and the parent gave these differing accounts each time he or she were interviewed, but that is not the case here.
IMO, wayyyy too much is being made of these discrepancies.