Another theroy:
The aircraft landed in TO/GA mode. As it was in TOGA mode, the A/T logic didn't take into account that the aircraft was on the ground (it is not uncommon to touch the runway during a GA). As the aircraft was in TO/GA mode the TR of the left engine didn't activate in spite of lever movement. (Is this possible???). Additionally the right engine needed time for spool up.
So, no TR on the left engine and slowly spooling up turbine of the right engine may have prevented the expected massive yaw during the initial phase of the landing roll.