Nothing underhand Andy.
Touching another car in parc ferme is against the sporting regulations and is punishable by a fine, the same as undoing your seatbelts during the slow-down lap, which Lewis did. Others, including Lewis have touched other cars before and nothing has been done about it.
A car which fails the technical regulations in parc ferme is punishable by disqualification from the session. Vettel’s car failed the technical regulations in Hungary with a fault in the fuel monitoring system, so they had less fuel than they had realised, and was duly disqualified from second place.
All penalties dished out this weekend have been online with the rules.