Since I'm not able to observe directly, I have to assume that the doctors were competent and did what they were supposed to do, and that the investigators also were competent and did what they were supposed to do. I wouldn't speculate otherwise unless I had access to documented evidence.
Since I worked as an investigator for thirty years, I'm fussy about such things and don't jump to wild speculation. I assume the professionals are competent unless there is evidence to the contrary.

-Joe-