No gun and barely even any Smashing!

It is possible to be outside the compound while within the destroy meter skipping the trigger of the semi truck lock in, however the end checkpoint at the garage is not active yet so it is basically useless.

Wii has a thing where with a given distance and not looking in that direction, walls are not rendered causing npcs to get out of bounds. Additional it shows how pathfinding and respawning work. It appears the game has a map of valid roads where if you have to respawn, it snaps to the closest road. The compound is not a road since a far tp. Additionally npc will stick to the roads to get as close as possible before going off-road.

Knowing this you can escape the bounds of a level, like the docks on "The Shipment" but the ending bridge isn't active until you do it normally :(