Corrected entry: In the scene where Dave invites Becky into his metal cage to show her the magic of his Tesla coils, he closes the gate, turns on the music, and hits the go button for the big lightening show. However, the cage they are in is called a Faraday Cage, and it is meant to cancel out or ground out all incoming electro-magnetic energy. There is no way the radio could have been picking up a radio signal inside the Faraday Cage, much less while the Tesla coils were spouting energy around the room. Unless it is on battery power and a CD, of course, but I remember him tuning it into a station. Wikipedia and many other sources will confirm this Faraday Cage.
Corrected entry: After being released from Grimhold, Morgana is ready to cast "The Rising" spell. She never actually learned it, or even saw the parchment with the spell, since it was Horvath who took it, then left. Afterwards, Morgana is quickly trapped in Grimhold - it means she doesn't know how to cast this spell, which she actually does like a sorceress supreme.
Correction: The only thing Morgana says to Horvath is "get the spell". However, the narrator says "and so it was, Morgana gained sorcery's most powerful spell." It's clear she knows the spell.
Corrected entry: It is assumed that Horvath uses the same mirror spell during the car chase that Balthazar used in the bathroom. If that's the case, wouldn't Horvath have been able to bring himself out of the mirror by entering his own reflection as Balthazar and David did in the car? (00:56:00 - 01:14:00)
Correction: Which is probably exactly how he got out. If the other side of the bathroom mirror didn't show a reflection, he needed to find a mirror/reflection to get out. All we saw was Horvath tell the kid to wake up his assistant, nothing about needing a spell to be let out.
Corrected entry: In the scene where Horvath tracks the Grimhold and kills the man in the car he mentions Chinatown. How would he know of the existence of Chinatown and refer to it by its common name after being trapped in the grimhold and urn for a thousand years? (00:29:50)
Correction: First off, Horvath used magic to see into the past to see who took the Grimhold. If he can do that, it's possible his magic lets him know where the man lived. Second, Horvath found David's apartment shortly after being released from the urn, so given that, he could have time to learn about Chinatown and figured the Chinese man who took the Grimhold lived there. And third, no timeline is given for when Horvath was locked in the Grimhold and given that Sun Lok was only in the Grimhold for 200 years, Horvath could have known about Chinatown when he was alive.
Corrected entry: As the film progresses, Dave's age changes from 18 to 19 to 20 when mentioned in bits of dialogue.
Correction: His age wasn't actually stated as each of those numbers, such as in the bathroom scene with Drake, Drake estimates his age as 20, and Dave doesn't confirm nor deny it.
Corrected entry: The scene at the end of the movie, where Balthazar and Horvath are facing off in Dave's Tesla coil laboratory, has Horvath throwing Balthazar across the room. Balthazar smashes against a large coiled copper contraption, and Horvath makes it curl the pipes around Balthazar's hands so he cannot escape. Balthazar keeps the bad guy talking and freezes the metal tubing, eventually breaking it and getting free. However, this tube is copper tubing. It is commonly used in labs when working with liquid nitrogen. Liquid N2 is at -200 or so degrees Centigrade (-346 F). If that touched his hand for a moment, it would have caused personal damage. Not to mention, copper tube doesn't break at that temperature, not with bare human hands trying to break it.
Correction: He's a magician. If he can defy the laws of physics by magically freezing something down to a point when it's capable of shattering, he can protect his hands while he's doing it. It's magic - factual errors don't really apply.
Corrected entry: When Dave is running down the hall and Horvath is preparing to unleash the wolves (pictured on a calender in Dave's apartment), Dave stops, as if he is hearing the wolves and/or has first seen them. But, Horvath hasn't made them appear yet.
Correction: Dave stops on the stairs and turns because he hears the zapping sounds as Horvath makes the wolves come to life.
Correction: The MIDI file controlling the Tesla coils was being played off of his laptop. There was no radio involved, and it would have required a very sophisticated program to convert any radio signal into a MIDI signal in the first place. In other words, this is not a mistake as the laptop is not receiving a signal from outside the Faraday cage.