IMO, the refs messed up prior to the procedural on this call. Unless there is an angle that hasn't been shown yet.. Staley did nothing incorrect to draw an Unsportsmanlike.. if anything, Matthews is lucky that he didn't pick that up as well with his couple swings. Amazes me every time that a players tries to throw a punch at a facemask.
Matthews made a mistake in timing of an aggressive hit.. I get he wanted to be aggressive and for most of the game, it was beautifully done. Just the timing of that hit, both in terms of game situation and play situation. Although I think even in bounce that probably draws a flag.
"The oranges are dry; the apples are mealy; and the papayas... I don't know what's going on with the papayas!"