Ummm... Funny though it is, it DOES worry me that someone in those (two, rather powerful positions) can sign something they haven't even read properly. [:0]
(Especially since it was only two lines above the actual "dotted line" [:?])
It seems a little odd to me as I guess the contract would have been a Boeing one (ie and American company) and pretty much every American I know would always refer to 1 stone as 14 pounds.
And I can't imagine either Legal team letting that one 'fly' - I know my legal team pick up on some weird stuff when contracts come in.
And I can't imagine either party seeing it as a joke. (Although, I can see Branson at least putting a joke spin on it if indeed he mistakenly did sign this)