1. it's completely unsportsmanlike.
2. it says you've spent the rest of the game trying to beat the other team but haven't found a way to do so, so now you try this desperate move involving none of your own players...
3. if you're going to allow it, make it a compulsory 15-yard penalty for doing so.
4. nobody wants to end a game this way.
5. if you're going to lose, do so with some fucking dignity. all the tributes to sean taylor yesterday and you decide to end the game like this?
in rugby, the losing side stands and applauds the victor off the field for beating them fair and square, joe.