The carriers are about to skewer themselves on this very point because they so often deliberately deal in bad faith with their claimants. They have both the right and the duty to investigate claims, but once their liability is established a whole new world is uncovered that insurance salespeople never mention. Or Heavy Sedation Getting statements from accident victims while still under the influence of anesthetics is a neat trick, especially when the first time the victim discovers it is in court and they don't even remember ever seeing it before, but the signature is theirs. The officers won't move against their own financial interests and haven't the insight to see that they are being used, soon to be cast away themselves. Studies have been done where the carrier pays only 80 percent of what they owe and send it with no comment.
Most people just accept that amount without complaint.
That's a real profit-making gadget. There are few businesses which couldn't thrive on an addition of 20 percent to their profit margin. Another one is to lose the file about three times. Unless there is a lot of money at stake, many people forget it. Another is to deny the claim with a nonsensical explanation.