I know this location & know of this "bug".
It's possible to leave but it's pretty difficult. You'll end up standing on the edge of the terraformed ground immediately in front of the stone floor, then you can jump forward to continue out. I was able to use this exit technique without a cart & was able to repeat it with a cart by dropping the cart close to the edge of the stone floor, then using it after egress.
In any case it's an excercise in patience to get out of the area.