A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
Bayushi Wateru's interrupt recieved a technical errata giving it the Absent keyword to ignore the Rule of Presence. Since Bayushi Wateru is obviously not considered in play at the battle location due to the need to add Absent to her ability, how can she ignore the Rule of Location to make her ability playable?
Ninja Absent Interrupt: After you Recruit Wateru during battle, take an additional Battle action.
There's no way you could use Wateru's ability if it didn't ignore the Rule of Location. You can't Recruit a card ""from" the current battlefield, it makes zero sense. Necessarily must the card be out of play, it can't work other way, so it is implicit that Wateru wasn't at the current battlefield. This is a similar case to Hidden Defenses being playable without Presence, because necessarily you couldn't have Presence to play it. Wateru works as written because the ability needs him to be out of play when announced. That's not the case with Absent, because it was possible to Recruit him AND have Presence thanks to other cards, thus the tech erratum.