There was a disagreement in RDT between some judges about how to read rules 702.7b-c relating to ninjutsu and first strike.

702.7. First Strike
702.7a First strike is a static ability that modifies the rules for the combat damage step. (See rule 510, “Combat Damage Step.”)
702.7b If at least one attacking or blocking creature has first strike or double strike (see rule 702.4) as the combat damage step begins, the only creatures that assign combat damage in that step are those with first strike or double strike. After that step, instead of proceeding to the end of combat step, the phase gets a second combat damage step. The only creatures that assign combat damage in that step are the remaining attackers and blockers that had neither first strike nor double strike as the first combat damage step began, as well as the remaining attackers and blockers that currently have double strike. After that step, the phase proceeds to the end of combat step.
702.7c Giving first strike to a creature without it after combat damage has already been dealt in the first combat damage step won’t preclude that creature from assigning combat damage in the second combat damage step. Removing first strike from a creature after it has already dealt combat damage in the first combat damage step won’t allow it to also assign combat damage in the second combat damage step (unless the creature has double strike).
702.7d Multiple instances of first strike on the same creature are redundant.

The situation as posed is:
Adam controls an unblocked creature and an Archetype of Courage, with a creature with ninjutsu in hand. He allows the creature to deal first strike combat damage, then ninjutsus in the creature in his hand. Does the ninja deal combat damage?
The crux is the lack of an explicit “creatures with first strike damage that have not dealt it yet will do so in regular damage.” The creature wasn't given first strike after not having it, it didn't exist in the first strike combat damage step.

Any help is appreciated. Thanks,
-Greg