In the 4th quarter of the Titans loss to the Chargers in London, Titans offensive lineman Taylor Lewan launched himself into a defender at the end of a play. Despite it clearly being a dirty hit it wasn't flagged.
This seems like a pretty clear cut example of a play that should be flagged. Lewan launched himself into a player who was not expecting to be hit.
Expect a fine and possibly a suspension to be handed down, although it is the NFL, so you never know what will be punished.