I have mixed emotions about this whole case. Although not personally verified by me, I saw reports that indicated he knew the trailer brakes didn’t work when he picked the trailer and load up. On almost any semi truck or trailer built in the last 30 years or more the brakes are a fail safe design. Spring pressure mechanically applies them and air pressure releases them. If they weren’t working then they were totally out of adjustment or had been caged. At the most basic level the driver is responsible for a thorough pre trip inspection to ensure that it is safe to travel or not operate it. I wish I could have heard the testimony from him and people who knew the details. I still have questions.