There's a rumour that the Jordanian pilot was already dead and ISIS just burnt its body. The reason behind this is that they (the exported wahhabis) unsuccessfully tried to negotiate with the Jordanian government for a PoW exchange: The pilot (they pretended he was alive) with a female martyr wannabe.

When the Jordanian government insisted on being provided with a piece of evidence that the pilot is still alive, they staged that fake execution, for PR purposes.

I don't find that theory very plausible, but I haven't watched the video, yet.