Schoology and Kami

After one student completed her PDF assignment on Kami, for some reason, the answers were visible on the original document that I posted to all of the other students on Schoology. A student shared that when he opened the link, he was able to see the answers. Is this because the student did not press send on Kami? Again, I opened the link to the assignment, and all the answers appeared on the original document. What is going on?