Back Row Block??

[DaveASA/FED]

Was watching a game last night and you know how you can always see better from the stands... well one team had a back row player that was coming up to the net (she was their server) and she IMO attempted to block several times. As I said she attempted to block, she never got over the net when she jumped but did raise her hands and jump as if to block. My question is is there a stipulation that you have to clear the plane of the net for the back row block to be called as there is with the back row attack?? Or would you all have called it?