Shane discharged the weapon by rapidly firing his gun and aiming it toward the lizard's knee while he was doing so.
The fire line wound its way upward, coming into contact with the thick skin; this caused some of the flesh to peel away when it came into contact with the flames, which led the fire line to wind its way higher.
At the same time that the disturbance occurred, the lizard's homeostasis was thrown off balance.
At this moment, rather than inhaling through his nose, he was doing so via his lips.
The lizard's already injured belly took the brunt of the swift barrage of fire strikes that Brian directed at it as he assaulted it, and it was the belly that took the most damage.
During the middle of Brian's onslaught, when he was connecting with five jabs and a straight blow, the lizard was driven forward by Brian's forward momentum.