There are a number of diagnosis codes that could appear in the record that have the meaning of "threat to self and others" that would not count as a valid exclusions. Since it's already rather infeasible to document this fact discretely in the record (as opposed to in a note) the fact that these are not counted magnifies the false negative rate for exclusions.
ICD-10 codes:
R45.5 Hostility
R45.6 violent behavior
R45.850 homicidal ideations
R45.851 suicidal ideations
(not an exhaustive list)