Because there is no recording of AK's statements, the 'guilty' side believes that Amanda came up with PL's name all on her own, that it was her idea to blame him, and that she did so with malice. And while that's a nice story to bolster the 'guilt,' it is in no way corroborated by anything that any of us can point to as a source. Therefore, the opposite is just as likely (perhaps even more likely) to be true.
The point is that none of us know how and why exactly PL's name went from being on a text message to AK accusing him of something he didn't do.
Sure, you can assume and imagine what you'd like. But proof? There simply is NONE.
So every time someone brings up PL's name as if it is a certain fact that AK decided all on her own to blame him and then when they go on to deny that there was any coersion (as if they'd actually know), these assumptions and imaginings are challenged by the other side.
Because when it comes right down to it....
NO ONE HERE KNOWS for a fact what LE said, how they said it, how that interrogation went down, and how it came to the point of AK pointing at PL and the rest of it. And if someone outside this case claim AK said something in that interrogation, without any proof, they are blowing smoke out of their you-know-where!
NO ONE.
SleuthyGal, you are right that no one knows for sure, but I think one can reasonably infer that PL's name was first brought up by LE because of the text message.
1. That's what AK has said. AK has not always been truthful, so if this were the only evidence it wouldn't mean much. But there are other reasons to believe her.
2. AK had no independent reason to implicate PL. Despite attempts to claim the contrary, there is no evidence of a grudge between AK and PL. She was scheduled to work on the night of the murder; she discussed changing to daytime shifts after the murder. Obviously, AK had not been fired. That she had no grudge against PL is apparent in the way she attempts to recant even as she accuses PL, by saying her memory of his involvement isn't real.
3. Accusing PL was very risky because, in fact, AK had no knowledge of where he had been that evening or what he had done. As it turned out, PL had a rock-solid alibi. It would have been safer for AK to blame a "bushy haired stranger" that the police couldn't trace than an actual person who could be traced and cleared (even though it took an eternity to do so) by LE. Guilty women who have made false accusations to divert suspicion from themselves (Susan Smith, Diane Downs) figured out it was smarter to blame someone who would never be found.
4. In accusing PL, AK had to put herself at the scene of the crime. Perhaps she didn't realize all the implications of doing so, but surely she sensed it was risky to give up her story of being at RS's apartment all night. She must have had some reason to believe that by implicating PL, she could mollify ILE. The most likely reason for her to believe that is that ILE was already suggesting PL as the murderer.
5. In accusing PL and placing herself at the scene of the crime, AK squandered the alleged hours she had spent cleaning up and staging the crime scene. As with #4, surely she had strong reasons to suspect that ILE would believe PL was the perp for her to give up all that effort spent on staging. As with #4, the most likely explanation is that ILE already suspected PL, probably because of the text message.
6. Finally, in accusing PL, AK offers little detail and nothing the police hadn't already assumed. This is consistent with telling ILE what it wanted to know, but not with confessing to an actual event.
(ETA You and Malkmus got to much of this before me, but I think I've added some arguments so I'm going to leave it. I misunderstood your point and thought you were arguing it was simply a mystery how PL's name entered the interrogation. Obviously, I don't agree with that. I think the evidence is largely circumstantial, but I think it's clear who brought him into the discussion.)