I have encountered this on numerous occasions. In some vases the client approached the lender and was able to ‘clear’ me so that I could carry out the task. I suspect, however, that most of the time this results from simple inertia: it’s what they’ve always said, or what the last person said, perhaps without understanding why.
I’d be interested to know whether the referral is warranted, because all too often I find it is merely the valuer passing the buck, especially when it concerns past structural movement. It should often be possible to draw a conclusion or arrive at a reasoned view. If that’s not possible it’s quite unlikely that another professional can either, except by monitoring over time.