Perché mi da un EV$Diff Negativo???????????

Andamento dalla mano:
Grabbed by Holdem Manager
NL Holdem $0.25(BB) Replayer
SB ($95)
BB ($45.77)
UTG ($15.32)
Hero ($24.65)
BTN ($47.31)
Dealt to Hero K♠ K♦
UTG raises to $0.75, Hero raises to $2, fold, SB calls $1.90, fold, UTG calls $1.25
FLOP ($6.25) 3♦ J♠ 9♠
SB checks, UTG checks, Hero bets $4.50, SB raises to $93 (AI), UTG folds, Hero calls $18.15 (AI)
TURN ($51.55) 3♦ J♠ 9♠ 3♣
RIVER ($51.55) 3♦ J♠ 9♠ 3♣ 2♣
Hero shows K♠ K♦
(Pre 81%, Flop 80.9%, Turn 95.5%)
SB shows J♥ 8♥
(Pre 19%, Flop 19.1%, Turn 4.5%)
Hero wins $48.98
E' solo una curiosità, ma non comprendo.
Ciao e grazie