Runaway Horses or The Domino Effect

I asked my stepson to cut the grass on Sunday.  He chose not to.  He snuck out and went to a friend's house.  I called my husband at work when I realized that the stepson was gone.  He called his son and demanded he go gome and immediately cut the grass.  The stepson returned home with two of his buddies and decided it would be more fun to shoot birds with his gun (a big no-no) instead of cutting the grass.
When he shot the gun it spooked the horses who broke the fence while attempting to jump over it as they escaped. 
One of the neighbor boys eventually caught the horses about a mile down the road.  The boy's dad called me and told me the horses got out.  I was in my car, about ten minutes away with about 20 minutes left of daylight.  I quickly drove home, grabbed two lead ropes and raced back to the location of the horses.  I  negotiated with the boys to help - a. get the car back home and  - b. get the horses home.  My stepson, always prepared to get out of too much work, opted to drive the car home while the other boys and I walked the horses through the water logged pastures (the rains ceased on the 8th day). 
It is now seriously approaching nightfall, the pastures are flooded, the horses are minimally cooperative and I can bearly see to find my way through the pastures.  After about 45 minutes of trudging through calf high water we made it to the back gate of my pasture, encouraging the horses along with a bucket full of sweet feed just beyond their reach. 
In the dark that has now engulfed us, I have to close off the back pasture because the horses broke the fence.  Early the next morning I have to buy a new gate for the middle pasture (10 foot galvonized gate at Tractor Supply Co. $95.00) because the old once is completely rusted and broken.  I have to move a 50 lb bag of chicken feed, a 50 lb bag or cracked corn and a 50 lb bag of goat feed to keep the horses out of it.  I have to lock the front gate to keep the horses from running into the road.  I have to keep the chicken pen closed to keep the horses from hanging out in there trying to eat everyone else's feed.  This prevents the goats from being able to access their feed as they are fed in the chicken pen. (Are ya'll following me....I'm still repairing everything from the domino effect of the stepson's initial irresponsibility.)  Has anyone observed up to this point in this story that the stepson isn't fixing the fence, hauling the 150 lbs of feed around or buying a new gate? 
Today as I'm caring for the horses I notice that their legs are cut up from the barbed wire that was around the fence that they broke through trying to escape from the noise of the gun that the stepson shot off instead of cutting the grass like he was asked to cut some 10 hours earlier. 
Soooo....I ask....who has to pay the vet bill?   I bet it's the same person who bought the goat feed, the chicken feed, the cracked corn, the new gate and the fencing to fix the broken fence.