This is fascinating stuff. In the United states, it is common practice to go and observe the surgeon you want to appoint, operate. In the UK, it is virtually unheard of - until recently that is. I was representing the Royal College of Surgeons at a appointments advisory committee to appoint a Consultant Heart Surgeon at a London Hospital. The medical director told me that it was common practice for him (the medical director - a non surgeon) and a senior surgeon to observe the potential appointee in their current workplace.
A formal assessment of surgical skills is made when trainees are interviewed for appointment to specialty training, both at ST3 level and at ST1 level. And yet, no formal assessment is made at the end of training when they are about to enter the scary real world or further on in their career as consultant when they are being assessed/appraised for revalidation. This paper suggests that there is value in doing so and I am sure the public would expect it.