Despite no new or changed rule in the rule book, and nothing in the rule book allowing this, read this new case play:
* 8.3.3. SITUATION B: During a non-kick try, A1 fumbles the ball, and in scrambling to recover the ball and avoid defenders, retreats into his own end zone where he is tackled. RULING: This is a one-point safety where B is credited with a point, and A must then free-kick as normal. This is the only means of B scoring points on a try.
So, B now CAN score on a try by A. And if the score is A leading 9-8, at the end of the 4th quarter with 0:00 on the clock, a TRY MUST BE ATTEMPTED because 'B' could score and tie the game up 9-9?