The Man They Called a Magician - S1-E2
Other mistake: In his training at the end, Jigen shoots over a dozen times with his revolver without reloading. (00:21:20)
The Man They Called a Magician - S1-E2
Other mistake: Despite falling unconscious at the bottom of the sea in his car and being rescued by Jigen, with Pycal within range since he got out of the car at the last moment, somehow Lupin gets to Pycal's home before he does, setting up a bunch of tricks in advance too.
The Man They Called a Magician - S1-E2
Other mistake: Lupin uses the three projectors to show Pycal the formula. To work, the projectors must carry one slide each, but then it turns out that Lupin had all three in hand the whole time.