"It upset our game plan a little bit but we do train for it, and we do integrate with our B team well, so it didn't upset us too much [overall]. We've got pretty good depth so the guys that came on slotted in well.
"Hora Hora certainly took to us in the forwards, they had a well drilled forward pack which picked and go-ed well."
Miller said Williams' head knock was not considered serious and was substituted as a precaution.
Hora Hora coach Mark Wati said the loss was not pleasing for his side, especially after having such a dominance over Kamo's forwards.
"Our forwards took it basically to Kamo," Wati said. "Last week they [Hora Hora's forwards] didn't clean out very well, but we'd done a lot of work on our rucks at training and you could see that [on Saturday].
Wati and Miller credited Hora Hora's centres, Warren Dunn and Vili Tahitu'a, for causing havoc with ball in hand.
Wati said Tahitu'a has had a positive impact for Hora Hora since making the move north from Auckland in just his second match for the club.
"As we get further into the season they'll [Tahitu'a and Dunn] start to figure out each other's lines and be a real force."
In other premier club matches, Old Boys' Marist continued their strong start to the season with a 33-10 win over the Western Sharks; Mid Northern made easy work of Otamatea, winning by 53-17; Mid Western overcame losing Ben Berridge to a suspected broken leg to beat Waipu 36-12; and Hikurangi pipped Wellsford 31-30.
In the reserve grade, Sharks beat Old Boys' Marist 12-10; Mid Northern accounted for Otamatea 22-8; Mid Western cruised past Waipu 25-7; Wellsford overcame Hikurangi 59-20; and Kamo took out Hora Hora 41-0.