This is a question for residency selection committees at academic programs. I was an MD/PhD student who graduated a couple years ago. After I finished my PhD, I was a witness in a fairly egregious misconduct case against my PI. As you might imagine, I did not request a letter from this individual. (I could not reveal why, as I was obligated to protect confidentiality.)
I later matched to a non-academic program which was low on my rank list. I am generally happy at my current program, but recent revelations have led me to worry that my PI may have influenced my match in a negative way.
1. Say you were interviewing an MD/PhD applicant at an academic program. If the applicant did not include a letter from their PI, would it hurt their application?
2. Would you reach out to their PI during interview/rank season?
3. If the applicant asked (some time later), would you reveal your answer to #2?