Hardly the case. True, the truck's trailer brakes were frozen and inoperable. True, it was unsafe to drive the trailer. So the driver unhooked the trailer, drove the fully operational truck cap to a rest stop, and saved his life. And got fired for it. He didn't break a law, he violated company policy.
Oh?
It seems the heat in the truck wasn't working properly.
Same difference. It went by the letter of the law/policy/whatever.