All that H&G can do is to try and recover damages from either/or RBS and the (then) directors. They cannot take any action against FSG or demand the return of their ownership. However should either RBS and/or the directors win in the High Court it would effectively shut H&G up as any further comment (even if made in the US) would be met with an action in the UK courts for either slander or libel (depending if the statement was verbal or written).
Should be a stroll in the park for Barca 1 little point though Stevenage are the only team not to concede a goal in this years FA cup COME ON STEVENAGE