in this thread I believe he was talking about hantei being run under Utaku Plains which states:
Utaku plains : Your Personalities have +1 PH and a maximum Personal Honor of 5 while in play.
Which is where he was getting the 5 instead of the 6.
Re: Utaku Plains - Personal Honor - Funeral Rites
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.