Holding on loose ball play

[BackJudge]

In reading the rule book on penalty enforcement, I have a question on a play.

A's ball 1st and goal at the 5 yard line. A1 drops back to pass. A5 holds at the 8 yard line. A1 passes to A2 in the endzone and it is incomplete. B accepts the penalty for holding. Is the ball marked off from the 5 or the 8?

I say the 5. A loose ball play includes the run(s) that precede it, making this a foul during a loose ball play. The basic spot for a loose ball play is the previous spot (in this case the 5).

I am being told by several people (including the referee of our playoff crew) that since the spot of the foul is behind the basic spot (all but one rule) you mark it off from the 8. The case book agrees with me (10.4.2B on page 77 w/comment), however rule 10-6 All but One Principle does not.

DOES ANYONE KNOW THE CORRECT ANSWER