My default with this kind of thing is now a progression:

a) "oh... can you EXPLAIN ____ to me, please?"

b) "I must have misunderstood... maybe you can explain it to me?"

c) "This is what I understood. Please correct anything that is inaccurate in this summary."

The last is by far the most aggressive-- that one belongs in full documentation, Letter of Understanding mode, particularly when such a thing is date-stamped, has a clear timeline and full names, etc. I do NOT employ that until earlier attempts have failed.
Schrödinger's cat walks into a bar. And doesn't.