Would this be why most of the attempts in a session turn out awkward?

Because the pupil is not clear on how to do it. He is unable to understand or follow spoken instructions so he does it incorrectly at first, resulting in the instructor telling him so and saying more things, causing him to need to guess because he still does not understand. Whenever the instructor praises him, he does not know how he did it; it may be luck. He does not get a chance to see it. Whenever he tries to figure out how he did it gracefully, the instructor senses that he lost control and even says so. And even after that lesson, he still possibly does not have a good feeling while doing it in private even tho he may have a slight idea how to do it but may be unsure if that is what the instructor would have looked for. Would this be why he tenses up: because he is still unclear? Or is the only cause him being observed?