Nun Slap ignores the hired monster's abilities until the end of the fight. If you look at the
end of fight rules you will see that the first thing that happens in the end of the fight. Then all abilities that happen or trigger at the end of the fight occur. This means that the Survivor abilities are no longer being ignored, as they do not trigger until the fight has ended.
Since Nun Slap is only in effect until the fight ends, and Survivor only happens after the fight has ended, they will not overlap in duration, so Nun Slap cannot prevent Survivor abilities from occurring after the fight.