who is at fault

Talk to your insurance company. You did report the accident, right?

Hopefully this has been reported to the Collision Reporting Centre and your insurer. The insurer will assess fault.

I didn't mention that after screaming obscenities at my daughter and scaring her half to death, he got her name and number, then jumped in his car and sped off. I called the police that night and they gave me several options, do nothing, file a driving complaint due to his behavior, or visit the reporting center the next day and have pictures taken. We choose the later, had the pictures taken, but had no info on the other driver. The manager advised us not to complete the report until we heard from the other driver. When his wife called our house she still did not give us his name or number. I tried *69 to see who called but only got a busy signal in response. When my husband asked what they wanted, she just kept listing things wrong with their car. It ended with my husband asking them to figure out what they want. Our car is 15 years old, and the damage is a very small dent on the back bumper. The collision center couldn't even find the damage till I pointed it out. We will not be fixing it. We are just super worried about what he is doing, re: claiming numerous problems with his vehicle. That's why the police advised us to have pictures taken right away. However it's been 4 days and he hasn't called back. This whole episode is just so stressful.

Hang on to that witness!

You did at least get contact information for the witness, didn't you?

yes we have that info, and still no more phone calls. his wife said something about avoiding insurance companies which makes me suspicious as well.

Definitely don't avoid insurance companies. If you fail to report an accident, they can later disclaim coverage (failure to report is a violation of the insurance agreement). Plus carriers can inevitably get you more money. This other family is trying to get away cheap and intimidate you. Don't let them.