Assumably the bus company would be buying the bus from a company with better quality control then the Chinese ones. There were some knockoffs "hover boards" that catch on fire and that Chinese bus fire.
Battery Management Systems aren't some new, developing technology. We know how to safely manage Lithium battery, it's just the certain manufactures are cheaping out on the battery packs and BMS. People didn't all stop using their phones because of the Note7 fires. People didn't stop driving cars because of the Ford Pinto. They need to get over their EV fears and be more discerning
It's the quality control and the fact that the buyer is a continent or ocean away. If a western company has hired a Chinese manufacture, they can get a good product if they stay on top of plant inspections. If not, the Chinese manufacture will start cutting corners. If you're a western buyer, buy from a western company even if a majority of parts were made in China. If you manage to import a whole car from Alibaba and something goes wrong, you're SOL.