You're right, there are lawyers that will file a lawsuit over a dropped hat, but the chance of it going anywhere is probably close to nonexistence so the attorney wouldn't get paid. The guy probably doesn't even have enough money to cover the expenses so the attorney would risk being out that too.
I think the case in Houston you referred to was the Joe Horn case but the castle doctrine was not the reason the Grand jury refused to chrge him. when he called 911 he mentioned he was going to shoot them as he was afraid they were going to shoot him.
There has been no castle doctrine case in dallas that referenced a neighbor
BUT that is not my point
my point is that a alwyer will file a lawsuit over anything, right or wrong