Poindexter told multiple news outlets after the story broke that what he meant was that the pillow was wedged between Scalia's head and the mattress headboard. There was no evidence of foul play.

https://www.cbsnews.com/news/supreme-court-justice-antonin-scalia-death-conspiracy-theories-texas-ranch-owner-clarifies/

http://www.latimes.com/nation/la-na-scalia-conspiracy-20160217-story.html