Your second point is probably the correct point, but hopefully we find out more with time. Battery fires are actually very hard to tackle so my guess is that t

Your second point is probably the correct point, but hopefully we find out more with time. Battery fires are actually very hard to tackle so my guess is that these busses were built to avoid catching on fire as much as possible so when one does happen, they need to investigate to make sure there isn't a major design flaw.