I study medicine, and have come across a few lecturers like that. We do both lectures, assessed by written exams, and practical work with clinical exams - I find the ones less willing to give feedback are those teaching the clinical aspect of the course.
Eg for written exams, our lecturers prepare a few mock exam questions and send them to us. After about a week, they'll email out a sheet of 'model answers' (though our exams never really look like the mock questions they send out). It's useful because you get to see if your thought processes have been correct, even if you haven't got the exact answer they're looking for.
For the practical aspect of the course, we have clinical reasoning tutorials. They'll do things like give us a patient history and ask us to work through investigations we'd do, likely diagnoses etc. For these, we are never given answers. The reason they give is 'we don't want you just memorising things'. Which is all very well and good, because medicine isn't about memorisation. But it gets to the point where you've come to an answer and have no idea if you've been thinking along the right lines / if you've missed something obvious out etc. I could have reached an entirely wrong answer and be none the wiser about it!