> The other driver was undocumented and he also preferred not to report.
I don't live in the US, so I don't know - but is that common? To me, it sounds like a significant accident, and I fail to understand why it wouldn't be reported.
The undocumented person may have not had insurance which would be one set of problems, or might have thought they would be at fault to some degree - being in an accident with someone injured would have involved police - both circumstances leading to contact with authorities could have led to deportation. It is not common to not have insurance but even in the case of people here legally, those without insurance commonly run from accidents because of the penalties for not having insurance. There is also the case of people with insurance but having a lot of driving penalty points (for speeding/running stop signs or lights) running or attempting to pay cash to avoid involving insurance because they have very expensive insurance due to driving history and do not want to get forced into an even higher insurance bracket.
I don't live in the US, so I don't know - but is that common? To me, it sounds like a significant accident, and I fail to understand why it wouldn't be reported.