Here Arena Trap's message is erroneously for the wild Pokémon on the right instead of the wild Pokémon on the left. This Pokémon was fainted and is no longer on the field, so the game regards it as a Bad Egg instead.
The trapping Ability flee glitch is a glitch in Pokémon Platinum, which occurs during Double Battles (then only possible via a Stat Trainer) when attempting to flee from a non-fainted wild Pokémon on the left side with Arena Trap, Magnet Pull (when the user's Pokémon is a Steel-type Pokémon) or Shadow Tag.
If the right-most Pokémon has not fainted, the game will state that the player cannot escape due to that Pokémon's ability rather than the Pokémon on the left side.
If the right-most Pokémon has fainted, the game will state that a wild Bad Egg prevents escape instead.
This glitch may not be a natural glitch due to a lack of a means of encountering or giving the wild Pokémon available in Stat Trainer Multi Battles Arena Trap, Magnet Pull or Shadow Tag.
However, the glitch is possible with Arena Trap (and likely Magnet Pull, unconfirmed but confirmed with Dugtrio hacked to have the ability) if a Dugtrio (and likely Diglett, Trapinch) with Skill Swap is created using the Mimic Transform Rage glitch.
- Schiffty (documentation via a randomizer ROM (2014))
- ChickasaurusGL (further research, video (2018))