Who the letter comes from is up to the Bank. Our process is our RMs are responsible for reaching out to clients and getting written responses and documentation requested by the BSA Department. It's their customer after all and they are responsible for knowing this type of stuff. I'm surprised your RM didn't know. With out RMs if money starts leaving our shop they are all over it as it effects their comp.
I, as the BSA Officer, would only get involved if it was something serious or complex was observed. It's been my experience that if a new person shows up and starts asking detailed questions most clients get confused and/or angry. This system works for us.
"100 victories in 100 battles isnt the most skillful. Subduing the other's military w/o battle is the most skillful." Sun-Tzu