Other mistake: When in the cave, Leia falls and is caught by Han. She tells him that "being held by you isn't quite enough to get me excited." As she is saying this you can see Harrison Ford mouthing her exact words. (00:44:05)
Other mistake: When Clark and Lois are on their way to the diner, the wide shot of their car driving along looked very familiar. In fact, it was footage used in the first movie, where the car was used as part of Lex Luthor's "real-estate" plan and was run on remote control. If you look closely in part II, no one is driving the car yet you hear Clark say to Lois, "Hey, you seem pretty quiet over there...."
Other mistake: The scenes with Flash and Aura in the shuttle are a complete mess. She tells him that the left lever controls direction, the right controls the altitude. When they are passing the planet Aquarius, she tells him to take a left turn over Fridgia. A) They are passing Aquarius at the time, not Fridgia. B) He moves the right lever instead of the left lever. C) The craft doesn't change direction or altitude and even if it had moved left as supposed to, they would have ended up crashing into Aquarius. The scene when Flash wants to talk to Dale is even worse. He pulls down the left lever to dive into Fridgia. It is the wrong lever. Then when he pulls back up, he correctly uses his right hand, but the right lever is already in the up position as seen in the previous shot. (00:42:15)
Other mistake: Near the end of the movie, Dave Speed jumps onto Torpedo's private plane and starts steering it to the ground. The plane is white with obvious red stripes. However, Dave Speed is supposed to lose his super powers when he sees red.
Other mistake: Cpt. Yelland and civilian observer Lasky are trying hard not to mess up with the timeline. Changing little things in the past could have tremendous results in the present/future. However they already disrupted the natural timeline by shooting down 2 Japanese Zeros, killing both pilots, leaving behind CAG Owens in 1941 and rescueing secretary Laurel Scott who would've been killed for sure by the two previously shot down Mitsubishi Zeros.
Other mistake: David is trying to locate the beast through a map of the city - for some reason, since he already located it before. Problem is, the movie is set in Missouri but the map he's looking at on his bed is a map of Los Angeles (you can even read "Granada Hills"). Similar mistake a few minutes later in front of the sewers; you can easily read "Monterey Park" to the right of a different map he props against the wall. (00:37:15 - 00:38:35)