I agree with Corona on points 1) and 2) and wouls alos offer the options...
3) they're not very good recruiters, so don't appreciate the gap.
4) they find it easier to get in contact/identify you than your boss and are using you to get info on you firm org chart so they return and contact a more senior person about the job.
Point 4) is why so many recruiters ask you "so at E&Y, do you work for Bill over in Ops Excellence?" you reply with "No, my practice manager is XXX, but my project manager is yyy and my mentor is zzz".
You think they're validating your position, but really they are scouting.