While I'm not sure of the veracity of this glitch (which is by Nico Kuriya) it might have been an obscure overlooked glitch. It might have been performed on Pokémon Stadium 2's GB Tower. In order to replicate the glitch then, it may be worth taking that and the revision (as Pocket Monsters Kin/Gin had two revisions probably distinguishable from a minor marking on the cartridge like the others; Red/Green, Japanese Yellow and English Crystal (which also has a newly documented Australia centric revision) into consideration; or it might just work regardless of these factors.
Translation of description: "The player doesn't seem to be able to leave (the train area). Please forgive the video quality. I'd like a high resolution version but I don't know how to do it."