The lizard saw Joel's uppercut coming, and went to deliver a swift kick, his muscular legs having the ability to break though foot thick solid stone in one hit. If the kick were to stop Joel even for a second in his attack, the lizard would have brought out another gun to shoot him several times. With the same setting as before.
The Saurian being busy, and fending off Joel, would have little time to react to Huriel. Meaning that when the sword was stabbed into his back, the sword would have made it through a seam in his Armour, how far Huriel could not tell, but judging from the loud shriek of pain the lizard let out, it was definitely enough to hurt him. The only downside being that the sword was stuck in his armour.