If I mention "PE" then miss one, a lawyer will zero in on it. Better to not give them help. Also, write the chart so the history/exam don't make it look like a possible PE.
I will tell you that this exact thing happened to me. It was a residency case: my attending got sued because I wrote all over the chart, time-stamped just a few minutes after I evaluated the patient, "STRONGLY SUSPECT PE."
We diagnosed it and the patient died anyways, but the point is, they used the fact that I wrote those words to say, "Why didn't you do XYZ at that point in time if you already knew the diagnosis...?"
This made me realize that they will try to use whatever you write to screw you.
(Thankfully, the case was dismissed before it ever went to trial though.)
I also think that you can just say in your deposition, "I always consider XYZ when patients come with ABC..."
Also, by listing some d/d in the actual chart itself, what if it turns out to be something NOT in that list?
My approach is not to list d/d and then I can just rattle off the standard d/d if deposed: "Of course I thought of..."
To be clear, however, this is all theoretical and I might be way off/wrong here.
Again, I just feel that the more you write, the more you hang. And I agree with the idea that negative tests are your actual best defense, as well as strongly worded disposition instructions about returning to the ER, etc. I often write, "All diagnoses are tentative in the ER and require close follow up and further reevaluation by your PCP," along with strict return instructions.