Security guard Scorby has always been Martin's chief tormentor. As such, he is one of the mutant fly man's main targets in the assault on Bay 17.
Even though Martin has already killed two scientists and melted a third man's face off, Bartok, intend on capturing him alive, forbids his guards for shooting him. Scorby is loath to obey this order, especially after Martin kills Scorby's fellow guard Hargis.
Eager for revenge against Martin, Scorby promptly disobeys the order not to shoot and begins stalking Martin through the lab. After a close call in which Martin's acid vomit burns Scorby's hand, making him drop his MP5, Scorby recovers his weapon and resumes the hunt. In his eagerness, though, all he succeeds in killing is loyal Barton scientist Dr. Trimble. He barely has time to process his mistake when suddenly Martin is upon him.
The gun is knocked away and the two struggle, but although Scorby is a big man, Martin is a seven-foot fly monster. He easily wins the brief tussle. One of Martin's upper hands seizes Scorby by the throat and breaks his neck. As if that wasn't enough, he then uses his lower pair of arms to forcibly bend Scorby's corpse over backwards, snapping his spine. He then hurls the body angrily across the room in a tantrum.
This death was highly unsatisfying. Scorby has a colossal jerk throughout the entire movie and his behavior called for a more gruesome fate than simply being snapped like a stick of celery. While comparatively innocent guards got pointlessly over the top, grisly fates, Scorby got too clean and bloodless a punishment.