Are you sure the feedback is on the same slide or are they
using branching to send you to a choice of slides with video on
them? I believe this is how you'd do it:
First, create a slide continaing you're video.
Then use the hide slide function in powerpoint so that people
won't be able to access the slide unless they go through the quiz
to get to it
Now craete a quiz question and use the branching feature to
go to that slide with the video
This is a very quick and dirty explanation, so please let me
know if you need more explanation or if you need more detail.
Best,
Jon