Pokemon Blue Glitch?

This is from like, 11 years ago, but here goes. One of the first few times playing Pokemon Blue version, I faintly remember my first hour in the game when the screen went black and I somehow teleported outside of the wall of the route directly out of Pallet Town, where you get your first pokemon. If you play the game, you can see the very gry area on the right side of the route outside of the wall. I was out there for a few battles, at which point i blacked out because my pokemon were too weak to continue battling, and because I was VERY new to the game. I'm quite curious if this has happened to anyone else? And if it has, does anyone know how or why it happened?