IANAL, sounds like you need to prorate the second line-item of distribution: https://legislature.vermont.gov/statutes/section/14/066/01205

As executor (I guess in this case because he had no will your title is technically administrator--moot difference), you have a right to access his medical records including billing under HIPAA. Make sure to be specific on format or they'll send you a bunch of gobbeldygook that's faxed, printed and rescanned into a PDF without text search or anything. I'm pretty sure you have to contact any imaging departments directly (you'd want to ask their records department) if they did anything like MRIs/CTs/X-Rays which they'd likely send you on DVDs in DICOM format with a viewer baked into the DVD.

You can also check the statutes to see if there was a time limit on the hospital making the claim.

There is a time limit to respond to records requests and if they omit anything requested without providing reason you can file a complaint with the federal Office of Civil Rights (OCR) which is the government body that enforces HIPAA.