I lost my mom last year, and I can't imagine what it would be like to lose one of my kids.
Not sure what jurisdiction you're in, but here are some things to consider.
1. The law on wrongful death in your jurisdiction. Many states have caps. Was the offer close to the cap?
2. Punitive damages. You don't get punitive damages for ordinary negligence. Typically it requires a reckless disregard for the rights of others, e.g. 66 in a 65 doesn't cut it, but 100 might. You mentioned that he fled. That is largely irrelevant - the issue is what he was doing at the time of the accident. What did the mediator think your chances for punitive damages?
3. Be realistic about what a trial will accomplish. Mostly it will be billable hours for the defense attorneys and experts. Chances are its not going to change how the company operates any more than the tragedy already has.
Again, my condolences.