As to having an engine failure the certification standards require that that a pilot of "average ability" should be able to control an aircraft following an engine failure. It is not such a big deal to lose an engine, assuming everything else goes as it should.
I just wanted to point that out, since it may come across to some reading this that there's some doubt about being able to fly a J41 on one engine. That is a requirement for such an aircraft to be acceptable for public transport.
You have nominated speeds which give you a safety margin so that you should be able to either safely stop or else fly away after having one engine fail. If you follow the correct procedures then you are reasonably sure of being able to safely operate free of the risk of a serious accident.
Here, obviously, more went wrong than just losing one engine but what exactly happened will have to be made clear by an investigation. There isn't much point in trying to guess what that is without all the facts, particularly the data from the so-called black boxes, one that records the flight values and one that records what the crew said and, secondarily, various sounds produced by power settings, switch selections, etcetera.
It usually takes about a year to a year and-a-half for the final report to be released because it is a painstaking process. Meanwhile people want answers immediately to the question of why a particular accident happened but it is impossible to do that. To point to a control being in a certain position, for instance: was it set in flight or was it moved afterwards? Only the Flight Data Recorder can answer that question for certain.