The headline is incorrect. The patient did not get stuck with a $25k hospital bill. The patient co-insurance was 20% of $25k or $5k. Still a lot of money for surgery and 2 days in the hospital, but not $25k.
Since the amount billed typically is several times the negotiated rate between a healthcare provider and an insurance company and the 20% is based upon what the insurance company actually paid the patient likely paid significantly less than even $5k.