One of the spinners is clearly sooted (would have to check which one), while the engine itself is away from a 'burned area'.
a lot of Black Sand around this Fan, so probably burnt after it hit the ground. (A very untypical burnmark for inflight tough.)
An to answer your question about burning inflight: It does burn inflight at a certain Area. Thats the principle...
Stop Kulverstukas video Post 923 at 2:23 full screen. Look at the top right of what appears to be the turbine section of this engine. Is that a big hole? Turbine disintegration maybe?
Its definitely not the turbine department. Even if, the hole wouldnt be shaped like this after turbine separation.
What we can see ist that the Blades overall are in pretty good shape. Which leads to nearly only two possible Conclusions:
1: Magic.
2: Turbines stopped working in Air, which means Fuel was out(possibly in combination with friction), which possibly means that the Engines separated from the body at an early stage of the event.