doesn't seem plausible.... her clothes were at home and her phone at home plugged in... doubt they'd think to take the phone and plug it in and her clothes
I think Ryan got drunk and went in to her house with intentions to rape her.. After all, he thought his other teacher was "hot" and sent her a message to tell her.
It is possible that Tara was going to meet someone she didn't want anyone to know about tho. She did tell people at the BBQ that she was going home to watch a video of the pageant, when no video existed. As we know, RD didn't have a cell phone at the time and also didn't have a car. It makes the whole him planning on meeting her thing a little impossible for a guy like that to plan . When I first looked up pecan wood on google one of the first things that comes up is how hot the wood burns at, it pangs of someone who knew what they were doing. RD abd BD were used to covering for each other even in high school... it sounds like they pretty much stopped hanging out shortly after Tara went missing. All of the circumstantial evidence would suggest that RD couldn't have planned any of it.