Factual error: At the conclusion, the island gets blown apart by a volcanic eruption while the children and the hospital staff watch from aboard a schooner off the coast. A volcanic explosion of this magnitude would have created pyroclastic surges that would overtake the boat, killing everyone aboard. (During the 1883 eruption of Krakatoa a pyroclastic surge stretched 30 miles to the coast of Sumatra, killing residents of some villages along that coast before the explosion that triggered the devastating tsunami (which killed over 30,000 people).
Revealing mistake: The sea creature Gorgo is paraded through the streets of London on a flatbed tractor trailer, and an off-screen American newsman announces the monster's arrival at Battersea Park, where it will be exhibited at Dorkin's Circus. The announcer introduces the creature's owners as they step from their motorcade, saying, "And our own Mr. Dorkin, of Dorkin's Circus, in the checkered suit." Problem is, Mr. Dorkin is wearing a plain gray flannel suit. Closeup shots of Mr. Dorkin over the next 40 seconds reveal that the suit is not checkered, not plaid, not striped, not patterned in any way at all. It's simply a plain gray suit. Apparently, the announcer's pre-recorded lines were never modified after changes were made in costuming. (00:34:05 - 00:35:00)Charles Austin Miller