That's not the rule
Like you, my "own" theory is that the gunshot was first because that makes sense to me, despite what the ME said. I also don't think the ME has an agenda or is a hired gun for the State -- I just think these circumstances may be an anomaly and are not amenable to a certain medical determination because of the decomposition.
In transcribing the ME, that Defense lady is crafty. She is trying to trip him up, she does get him to contradict himself, but he is coming back and solidifying his "thoughts" on some things. Juan has not gotten up yet. Love this M.E., calm and collected, I would prefer he was a bit more solid on some things like when this occurred (not 10 years ago, its 4 years ago) Guestimating his age and 6000 autopsies, we might be talking 200 a year. Granted, some take 20 minutes, they are heart attacks or obvious causes of death, so they can do several in a day.
I'm a bit confused as he indicates he never spoke to anyone after the day of the autopsy and does not recollect who was there, but since the report indicates who is present, then he agrees with what he documented.
That's good and bad. Good because it shows he is not having this overly close relationship with the prosecutor.. he did the autopsy, here it is, now you do with it what you have to. Bad because I would like his office or assistants to have prepared him a bit more on the details.
After 28+ years getting a doctor here and there, prepared for a deposition, they are so busy with patients (or autopsies) in this case, I understand that prep time is not always possible. I'm anxious to now get to Juan and see how it goes.
Some "points" are just kind of unclear or way too speculative given what they had to work with after decomp. set in.