Essentially that. There is a risk a skipping a majority of the proof and hence a majority of the points, but point-wise it would work out better than handwaving

Essentially that. There is a risk a skipping a majority of the proof and hence a majority of the points, but point-wise it would work out better than handwaving the step and getting negative points. It's been about 25 years, so my memory is a bit fuzzy, but it was an analysis class. I don't remember if I ever availed myself of this. I did have a classmate who completed, but didn't turn in his homework a couple of times. (I don't recall if it was the entire problem set or just a couple of problems that he omitted, but he got the paper out to consult while the prof was going over the answers.) The teacher was competent but quirky - he also required the students to purchase a stapler (to staple their homework) and locked the door after class started (if you were late, tough luck).