When Sinbad sets out to reveal the baboon to Melanthius, Melanthius opts instead to demonstrate his telepathic powers by identifying the concealed creature without looking upon it. As he does so, he describes it as "an arboreal anthropoid of the genus, Papio", a taxonomic classification that would not be established until 1777.
During the time that Zenobia transformed herself into the seagull, the locket is visible with the magic elixir around the seagull's neck, but when the seagull is in flight, the locket is nowhere to be found.
During Dione's introduction on "Casgar" (after she calls off the rock-throwers) there are two reaction shots, one of Hassan, the other of Maroof. These are obviously from the later "Hyberborea" segment. The hilly backgrounds and the fact that Maroof is suddenly bare-chested give the inserts away.
When the group go off in their boat, there is a view of a waxing crescent Moon, i.e. about 3 days after New Moon. We then see the Moon at First Quarter, which is 7 days after New Moon, and a couple of minutes later a view out of the entrance of the ice cavern shown the Moon as a waxing crescent again.
As Zenobia is traveling down the ice cavern by boat with her son, she is wearing black gloves in one shot and then in the next, they're gone. Cutting back to the original angle, they're back on once again.
The foreground characters and backgrounds (of Petra) are in focus, yet the characters in-between are out of focus in almost every single blue-screen shot set outside Melantheus's castle. This is optically impossible.