Will Fraser, physicists and engineers seldom employ the word deceleration in my experience, as an engineer, unless talking to lay persons. A deceleration is simply a negative acceleration. Hitting the water imparts a (very) high negative rate of acceleration.
Please give it a rest. You can't seem to tell the difference between facts that can be checked against evidence made available and rumors leaked by unauthorized people wanting their moment of fame. If you can PROVE your contentions about the Brazilian leaks being facts, then do so. Otherwise, please drop it. The facts so far pulled from reports suggests that the plane did not magically transport itself backwards tens of kilometers along its path and then fall apart in the air. And no other scenario of break up in the air seems to fit where the plane could possibly have been and breakup in the air as you insist. It must have been coming down very fast with a pull up attempt right at the bitter end to support takata's data, the timing data derivable from the ACARS, and the apparent condition of the plane.
It would be nice to know the condition of the passengers, too. A cultural and communications snafu got in the way of BEA getting the autopsy reports. And it had a deadline by law for issuing the report while they were still in the field trying to collect what evidence they could. They were too busy to sit down a please everybody with a very complete report. And they were not required to present any conclusions at all. That they did vouchsafe us with an opinion is stepping beyond the minimum requirements of their charter.
JD-EE