Unless the person has been going faster than 20mph at a turning radius of more than 30ft for more than a few seconds, it's unlikely to be a car accident. Whethe

Unless the person has been going faster than 20mph at a turning radius of more than 30ft for more than a few seconds, it's unlikely to be a car accident. Whether the accuracy and sampling rate are always sufficient to distinguish these (or data could be cached with look back at high-g) I don't know. That excludes most human only activities. Of course roller-coasters and various other rides could still trigger it.