[squirtle24]

In jets, the compressor is usually powered by a turbine, but there's no turbine here at all. Most of the thrust is coming from the electrically powered compressor. Would've been interesting if he had been able to measure how much additional power the flaming gas added.

[Daz1]

It can still be a 'jet engine' like a motorjet which is basically a reciprocating engine spinning a compressor.