Coming back to this again - I don't have anything definitively useful, but I wanted to get all the extra info I have into this thread.
- Clipping into things: I've had another report of this in a discord server I'm in, this time at Lappy Lake. They apparently hit the corner of the slope that goes into water on the main island and was able to swim through land. (Version: Wii, Dogz, PAL)
- Wrong Warp: found this video a while back. The part that's interesting is at 3:15.
The player is sent to "Jade Fields" from the Jade Fields entrance, but they appear into the void and the Sky Heights music plays. Unfortunately the uploader couldn't provide much more info - they reset straight after discovering it. There's no way of telling if this is useful unless we can replicate it, and it could even have just been a hardware issue from the uploader, but in my opinion it's worth sharing. I wonder what the minimap might've shown if it were turned on? (Version: Wii, Dogz, NTSC-U)
- Evading quest system: Something I might actually be able to look into. The guy who discovered early Lonesome Park has recently figured out how to switch around maps, so if I replaced - say - Jade Fields with the map and NPC info of the Dimensional Rift, we can find out if entering the area is the trigger. ...That said, given what we've learned about the game, something tells me that the conversation with Theophilus is the trigger, not being in the area.