Why Did Michael Light the Torch?

[The Cube]

A very weird sequence of events in that final scene.

First we hear a twig snap, presumably Michael stepping on that twig.

Then we hear one person running, but not making any vocal sounds. Again, presumably Michael.

Then we see the shadow of a single person as the running stops. This is Michael for sure.

Then he lights the torch, and starts running again, this time panting loudly in exhaustion or pain.

When he lights the torch, from Jack's vantage point, the torch is clearly seen.

So we must assume that Michael saw the fire.

We can speculate:

1) Michael had been running for some time. Hence the exhaustive pant and collapse.

2) The others camp was a far distance away. We can be pretty sure Zeke would draw "the line" at a safe distance.

So my question is, why did Michael light the torch when he did? Did he choose to do this?

Does this show he escaped from their custody?

Or that he was spying on them, and never captured? (As might be the case if he was indeed secretly communicating with Walt)

Or something else?