When on the boat looking at the monitor during close-up shots, there is a boat and a large mass moving through the water. When panned out, the screen is clearly on, but there is no picture. But when they go back into close-up, there is the boat and large mass on the screen again.
The emergency radio on the bridge shorts out when the boat begins to flood and the boat's generator goes out. Emergency radios work on internal batteries to avoid just such problems.
When the baby squid is shot to death, it bleeds red. Squids, being molluscs, have copper-based blood rather than iron-based, resulting in blood which is a milky blue or teal in colour rather than red.
Squid don't roar.
When Lucas Coven's (Larry Drake) boat goes down, an underwater view shows wooden debris sinking. The wood parts should float.
The squid emits ink when attacking its victims. Squids only emit ink defensively when fleeing.
Whip states the largest whole squid carcass ever found was 45 feet long, and that no one knows how big a squid gets. While the first statement is not strictly true, it could be Whip's error; the second statement is true, since squid are not generally visible.
In several scenes helicopters in flight have their doors open, but there is no breeze or wind inside.
Whip, the local fisherman, is regularly consulted and kept up to date by the Coast Guard, the scientific community, and the town politicians.