NOBODY is liable. Liable means, negligent.
Each property owner is responsible for his own damages. This attorney will probably try to send a couple letters, but there aren't any grounds!! Your boyfriend's liabiltiy policy will NOT pay, but they WILL cover his defense costs, if this goes to court. So I wouldn't worry about it if I were him. Even if he gets sued, the judge will find in his favor. He wasn't NEGLIGENT!! And he won't be out of pocket, except for his property deductible.
agent, 21+ years