play that just happened.
I think it would be more fair to make it worth 6 points like a touchdown. Its kind of like an own goal in soccer or hockey, which is still worth one point. In basketball if a player accidentally knocks the ball into the hoop which they are defending, its worth 2 points for the other team (which is the equivalent of an offensive score by the other team).
(note: edited to clarify for the basketball analogy)