what did he do to my car?

[BleedingHeart]

the other day, I went to work and inadvertently left my lights on. Later that night, I had to call an acquaintance of mine to come jump me. He said, condescendingly, "let me get in there, I'M the mechanic", and then proceeded to reverse the polarity, attaching his + to my -. It shot sparks everywhere, I called him an idiot, and then my car wouldn't start. I checked my fuses and discovered a blown 100A fuse that protects my alternator. I replaced that, we jumped the car, and it continued to run just fine. I drove it home, turned the car off, and just to play it safe, tested it out. It wouldn't turn over. I discovered that he'd broken a bolt on my negative battery terminal. I replaced that, jumped it again, left it running for 10 minutes while I showered, and then went off to work. I turned the car off, tested it again, and sure enough...it won't start...Any ideas on what he may have done, and how I can fix it?