A passive line vs a super maniac

He has 100% vpip and 19% pfr over 22 the hands I've been at the table. Sure, it's a small sample size, but I've been watching him play and I'm confident calling him a super maniac. The rest of the table is afraid of him except for SB, who is also a maniac but somewhat less so than him.

Inter .25/.50 NL $50 buy-in

Seat 1: MANIAC <button> ($46.78 in chips)
Seat 2: SB ($56.52 in chips)
Seat 3: BB ($47.75 in chips)
Seat 4: UTG ($58.40 in chips)
Seat 5: UTG+1 ($28.25 in chips)
Seat 6: KING ($51.10 in chips)
Seat 7: MP2 ($36.38 in chips)
Seat 8: MP3 ($27.10 in chips)
Seat 9: LP ($19 in chips)
Seat 10: CO ($26.90 in chips)
SB: posts small blind $0.25
BB: posts big blind $0.50
----- HOLE CARDS -----
dealt to KING [J /images/graemlins/spade.gif Q /images/graemlins/heart.gif]
UTG: folds
UTG+1: calls $0.50
KING: calls $0.50
MP2: folds
MP3: folds
LP: calls $0.50
CO: folds
MANIAC: raises to $1
SB: folds
BB: calls $0.50
UTG+1: calls $0.50
KING: calls $0.50
LP: calls $0.50
----- FLOP ----- [6 /images/graemlins/club.gif Q /images/graemlins/spade.gif 8 /images/graemlins/heart.gif]
BB: checks
UTG+1: checks
KING: bets $5
LP: folds
MANIAC: raises to $10
BB: folds
UTG+1: folds
KING: calls $5
----- TURN ----- [6 /images/graemlins/club.gif Q /images/graemlins/spade.gif 8 /images/graemlins/heart.gif][9 /images/graemlins/heart.gif]
KING: checks
MANIAC: bets $5
KING: calls $5
----- RIVER ----- [6 /images/graemlins/club.gif Q /images/graemlins/spade.gif 8 /images/graemlins/heart.gif 9 /images/graemlins/heart.gif][9 /images/graemlins/club.gif]
KING: checks
MANIAC: bets $7
KING: calls $7

Comments on all streets appreciated. Also, are you more likely to trust low-sample-size PT stats when they are at an extreme, like in this case?