The Magician - S3-E4
Revealing mistake: When Oliver meets Thea at the Grind and Jot Cafe (Which looks unsurprisingly like CC Jitters) you can see the cups on the table are from CC Jitters. (00:20:50)
Revealing mistake: When Wan pets the cat deer for the first time, the animal pushes his head under Wan's arm. The horn then goes right through his shoulder. (00:17:55)
Revealing mistake: When Grapefruit cannonballs into the pull, it splashes on Pear. But no sign of any wetness is seen at all on him or the diving board.