Lost internet connection after the show!
Ok. My "opinion" only: Top 3 have been pre - determined. At what point the contestants know, I'm not sure. I believe all along the two Davids' have been headed to the finale. Up to the top 4, there is wiggle room, based on ratings and votes cast. Jason, I think was supposed to go out at 5, but because of the note card reading incident, they pushed Jason through. I believe his bags were packed 2 weeks ago and here is why:
Jason, has had a few songs go to the top of iTunes. Both Davids' have several and Brooke has had quite a few too. The rest, have had 1 or 2 at the most, Syesha has yet to crack the top. He still has potential to sell a lot of music but will probably be "indie" like Elliot. But, please don't forget - this is a TV show - it is all about ratings and who will sell the most. Ratings are down this year, they have to keep who they think will bring viewers. Demographics also factor greatly in viewership. So, in a nutshell,
I think the writing on the wall for Jason

If he stayed tonight, he would split the vote with the 2 Davids' next week and they can't have that. If Syesha stays, Jason's fans will vote for a guy vs. Syesha.
Interesting that a writer for E! Online attended the dress rehearsal before the show yesterday and they said Jason was the best, connected with the audience and couldn't believe what happened the live show. I think Simon's scathing remarks affected Jason. The Bob Dylan song was his best - no forgotten lyrics in rehearsal, so I believe the criticism shook him.
Behind the scenes? David A needed more focus on him last night to make it look more even between the Davids', hence David C. stepping into the background.
If I am wrong, I will eat my hat!