I love all the speculation. Maybe it was stolen and burnt by the thieves, or was it a flipper who was going to loose too much and touched it
Don’t think you can definitively say that. There isn’t spinifex there, but if they have been playing in soft sand in the dunes and beach all day thay could have picked up some grass and dried seaweed etc around the DPF and then if it had decided to do a burn it could look just like an engine fire.
Anything is possible, but the position of the DPF makes what you're suggesting unlikely.