imported e-motorcycles

How can we determine if our electric motorcycle had a BMS? We imported 2 electric motorcycles in late 2010. They were ordered with a 5000W motor and 72V90AH LiFePO4 battery packs with a BMS. They were routinely charged and test ridden. One bike had about 500 miles. A few weeks ago, it was ridden 20 miles and parked. Approximately 50 minutes after the ignition was turned off, the bike burst into flames and was demolished. Fire marshall determined no signs of foul play. We trying to determine the cause. We are speculating that the battery pack was NOT LiFePO4.