It's interesting, in that you want someone who is familiar enough with what's happening and doesn't lose touch, but you're right, there is that potential conflict. I think a lot of it is also going to depend on the people around the intelligence commissioner and the support staff they actually have.
The intelligence commissioner is going to have considerable responsibilities on review and oversight. I believe the advantage is going to be having someone who has recent experience and understands the context and things like that, but even more importantly, I think ensuring that the people around this individual are well staffed and well funded is going to make a difference.