The insurance company may well have already done that; this is being put by someone who is suing them and looking for reasons that the AI bot is bad. The article is silent on what the company response to the accusation was and, realistically, we'd expect the appealed denials to have a very high rate of error whether determined by bots or humans. Few people indeed are going to waste time arguing a hopeless case against an insurance company - this is classic selection bias.

What do you think the claim approval rate is? Less than 10%?

It stands to reason that the overwhelming majority of cases where the claim was approved were approved correctly. Unless that rate is well under 15%, it’s impossible to have the claimed “90% error rate”.