The first thing to due after any accident is to contact the police. After that, if the other party is "at fault," you will need to contact his insurance company. Or, in this case, you will need to contact his company's insurance company. Because it was his property that was damaged, you will obviously need to let your brother know about the accident. I realize there extenuating circumstances involved with this accident. Your best bet is to seek legal advice to help you with this accident. In the future, you may consider purchasing a "non owner" policy. These policies are for people who drive occasionally but do not own a vehicle. These policies typically include liability, medical payments, and uninsured motorist coverages. (This policy will keep you from having to worry about adequate insurance for the vehicle you are driving.)