For me I find those first interviews with Law Enforcement to be where you get some of the best information. It's before the lawyers are involved, before the police has told the press what they know and before the person interviewed has really think about a story, you know really digest what they want to say. In hindsight we have the benefit of seeing what they chose to with hold, what they chose to divulge to the the LE individual. (For instance I believe Cindy Anthony's series of 911 calls was the most raw and honest she had been in the entire case)
That being said as far as SA's case goes, in his initial interviews he seems to waiver if TH ever came to knock on his door, how much he may have called her and if he touched her car in any way. The time line was off by several accounts. For SA's interview being she was there 2 to 2:30 and other witnesses 3:45 or so. For him to be viewed in the best light by the detectives he has to have minimal interaction with her for the least amount of time earliest in the day. So he minimizes it all. He claims his 4:35 call to her was in regards to another vehicle he wanted to sell. Is it possible he arranged an unscheduled photo session with her earlier during the 2pmish van photo session? For instance if she said she had another photo session scheduled (Zipperers) but she could come back after. Would there be enough time for her to go to Avery's spend 10 or 15 mins on the van, go to the Zipperers and spend 10 or 15 mins on their car and be back after for whatever SA was trying to sell? And be back at the Avery property for the 3:45 sighting? For SA to admit to that he would admit to her being on his property not once but twice during that day. And there would be another opportunity late in the day for the assault to occur.
I'm not saying he's guilty, I'm still on the fence but there's no proof that she ever made it out for the second time, there's not even 100% proof he was the last person to see her that day. I was kind of hoping for a bill of sale, receipt, or log for the unscheduled photo shoot.