I think the video is fake but the event was real.
You can't see IR but if it interacts with electrons present in ambient molecules they can undergo transitions and then release the energy as they transition back to their resting state via other states.
That's just a theory, gotta see if it's true in reality. 'Cause you need insane amounts of power for normal air molecules to generate visible light, like lightning. 'Cause even heat is just IR.