I find it amazing how much wild speculation goes on here over crashes when a bit of patience should see all the questions answered.
Just think how you would feel if you were being held, under suspicion, with your fellows here mulling over what you might have got up to that would cause the deaths of over 150 citizens of the country that was holding you.
When I read that the crew admitted doing something illegal all I could think was, 'Oh, sure.' You think someone would be unprofessional enough to do something like turn off the transponder and play around on an airway but then ADMIT to that? That doesn't make sense on the face of it. Either you play it straight and tell the truth or else you screw around and lie about it. To first screw around and then play it straight is not normal behaviour, so that quote seems unbelievable on the face of it.
It sure is strange to see this relatively small, lightly damaged Embraer and the relatively large, crashed 737; a logical explanation is hard to come up with and that makes all the more reason to just wait for the official report, when they can use the CVRs and FDRs to tell us what really happened.
We went through this once before in Nigeria when that 727 was sent out of control in response to a TCAS RA. We had eyewitness reports of the aircraft 'hovering' at Murtala Muhammed Airport, from a man of the cloth, no less, 'inside' information that the previous crew had refused to fly the accident aircraft because it was unsafe, that an engineer had been seen working on the hydraulic flight controls just before it departed on its ill-fated flight and so on. The final report was a real anti-climax; who would have guessed that the crew could have lost control in such a way? But there it was. This one might be like that, something we wouldn't have thought of initially.
I find the reports from Brazil to be useful. The speculation less so!