[ljudge]

Only team A can be awarded a 1-point safety on a try in federation. If you look closely at the rule it says something like "a safety by team B" (My rule book is currently tucked away).

And, for team A to score a safety it's incredibly remote. It would have to be a MUFF by B of a loose ball after a ball hits the ground on a team A fumble. The muff would need to be judged as the NEW FORCE which puts the ball into B's own endzone thereby giving team A a 1-point safety. If B happened to ever possess the ball the ball would become dead immediately. So, for example, if A fumbles and the ball richochets off team B's leg and ultimately into B's pylon you simply have a dead ball with a try that's no good.