This was one of the certification RTO/ EVAC test for the A340-600. The voices one hear are those of the test pilots who first do not want the fireman to extinguish the fire as time has to be measured and for the test to be successful it must not be less than 180 seconds I think.
The lone fireman so early is in fact a nuisance .
What did go wrong in this test is that the Tyres fuses did malfunction .
Later when the fires are larger and have to be estinguished, there were far more firemen , but approaching from behind and invisible by the video camera.
The ladder request is for the crew to exit the plane ( foreseen but not in place ) I do not think this was meant for public diffusion.
In fact this iwhole thing is part of a normal testing process.