With all due respect to a number of well-intentioned but not well-informed opinions that have been posted which are suggesting that bigfish17 get involved in a hardball contest with a large insurance company, you are not doing him any favours.
No-one would suggest that he just roll over and take whatever they decide to do, but this is potentially a $70K + payout and no insurance company would regard that as small potatoes?.well OK, maybe Lloyd?s of London

)
They are bound to do a reasonably thorough investigation as simple due diligence. The premiums that we all pay depend on this.
There have been a number of posts stating beyond question that he has no requirement to provide any info and he is somehow being victimized, and if he called the state authority having jurisdiction, they would set him straight!
Well, guess what?
The two
good pieces of advice so far are :
1) Document everything?.especially requests by the insurance company and your responses to them.
2) If you are not comfortable with the process, consult an attorney.
Everything else is just going get your file put in the slow lane. It has been three weeks if I read the first post correctly, and that is not a long time for these matters.
I have a friend who insists on the confrontational approach with just about everyone. Police, license agents, and even revenue Canada (our IRS) . He can?t seem to understand why he never gets a break on a ticket, gets poor service, gets audited?.etc.
If you want the insurance folks to cooperate with you, it works both ways.
And if confidentiality of information is your concern, any insurance company in Canada that allowed any info provided to it, in confidence, to be misused would be liable to penalties that would make this claim seem like loose change.
The US is even more rigorous than are we.