The boys saw the renegade clutch at his clothing, saw the cloth hold for an instant, then tear away under the impetus of the boy's movement, and heard Fremont's answer to the call as he struck the ground under the window.
Instead of going through the outer room and leaving the hut by means of the door, for some reason Big Bob concluded to follow the boy through the window.

The opening was large enough for the passage of his burly frame, but he was clumsy in getting through, with the result that Fremont was nearly beyond the circle of light when at last he came to the surface outside.
Then the renegade made another mistake, a fatal one.

He lifted up his great voice in warning the boy to return, and fired his revolver into the air as a means of intimidation.

As he did so, the door of the hut, situated on the east, flew open and the outlaws rushed out, doubtless under the impression that they had been attacked.

They left the door wide open, and a red square of light lay on the rain-soaked ground before it.
The only members of the party who did not exit by way of the doorway was the messenger who had identified Fremont.