The interpreter for the deaf during the speeches at the Mandela memorial wasn't signing at all but just "flapping his arms around."

The national director of the Deaf Federation of South Africa said the man was "moving his hands around, but there was no meaning in what he used his hands for."

It was not immediately clear how the bogus interpreter slipped onto the stage during the memorial service, where nearly 100 heads of state attended....

Experts agreed that the imposter interpreter was not signing American sign languages or any of South Africa's 11 official languages.

It seems funny for about 5 seconds, and then you realize that this marred a funeral and that it reveals a lack of security. 

(In the comments at the link: "I knew something was wrong when I saw him make the clipping sign and then the first down sign immediately after.")