We are talking about ones on the roof.
There are 5. Have you heard anything about others anywhere else? Did they mention finding none on the ground?
I am posing alternatives to where others may have ended up. I don’t know, nor honestly care enough to spend my life digging for details on the aftermath.
I found the longer vid. released by Senator Grassley. At ~ 4:48, 5 casings are counted, closely grouped “right there”. At 24:07, casings are counted again, with 5 on one side of the roof peak, and 3 on the other side. Looks legit.
https://www.youtube.com/watch?v=zzepkf9iUTk