See, one of the problems is that this all happened in a home setting by a private physician, giving non standard care and all very much 'under the table', if you will. There are definite standards for medical record keeping but the medical care is given either in a hospital, a clinic, office setting or if given at home there is some sort of professional agency involved. In other words, there's nothing shady going on. Yes, doctors certainly should keep records and must. BUT what murray was doing was not your usual medical care and I'll bet the last thing he would want would be the possibility of a paper trail to incriminate him if something were to go wrong. Which it did.
Of course, it IS entirely possible that he did keep some sort of record but removed said records when he was supposed to be resuscitating Michael. He could have been jotting down notes on a small pad as to what he gave and when, something like that would be easy for him to put in his pocket.
If he did any blood work on Michael, there would be records in some lab somewhere but to find them? And if murray used a fictitious name? Impossible.
If he did an EKG, used a portable machine, he would have the results in his hands.
So if you're thinking that there might be records of what he did to Michael somewhere, even if there were, I suspect they are long gone by now.
I doubt he kept anything that will ever see the light of day.
As for it being a crime to not keep records, I don't think it would be a criminal offense, more of a malpractice issue.