broke 4 lances before unhorsing ser arlan of pennytree

In The Hedge Knight, Ser Duncan corrects Prince Baelor by asserting that Ser Arlan broke seven lances against him, while Baelor remembers four. Could this discrepancy stem from a difference in how they count—specifically, Baelor referring to four lances each (totaling eight passes), while Arlan counted the total number of lances broken before being unhorsed on the eighth?