During Ash's battle with Greta, Greta told her Medicham to "use dodge", as if it was an attack. In reality, dodge is a battle tactic used in the anime to avoid attacks.
Although Ash tells Snorlax to use Protect, the move animation is that of Harden.
In a lot of the scenes during Ash's battle with Greta, Snorlax's feet were the same color as its body.
Inside the Battle Arena, everyone is barefoot. However, May is shown wearing socks in one frame when she should be barefoot.
Scott mispronounces Cianwood City while telling Ash about Greta.