My guts about this is that it's sometimes taking about a risk. It's a bit like applications really, you don't know how well people will do, so that's why you give them a trial. In some cases it's all about taking a risk here and using the same principle. However, trust bumps this down as it is a senior position, moreover dedication. Normally you can tell by the way they act how well they will cope under a senior position, however if it is still very vague the department has every right to bring someone back in. If it'll do the department good rather than destroying some parts of it somehow, they should do it. Of course, like Mike said, some departments work differently, as he said in the Competitions Department you need to reapply but you don't have a trial, regardless of your position just to see how much effort you will put in. All in all, 95% of these "returnees" have multiple reasons why so, just to maintain a high standard in the department, I would guess.






















