Talk Fantasy Football

Bakunin wrote:I would say it becomes pretty clear, that if stab is not something you change, when you can block and have to declare it, but you simply stab when you could. Then Stab is not a block (exchange for a block), then it follows from the GFI rules that you dont have to GFI to stab.

It is pretty clear however that Stab is something you do instead of a block. Therefore, in order to Stab you must be eligible to Block which includes being the appropriate action (Block or Blitz) and having a movement point available, via GFI if required, during a Blitz action.
The fact that Stab entirely replaces the Block, means that Dump-Off does not trigger as strictly written. That interpretation does not seem entirely unreasonable to me, even if it may not have been as intended.