Pokerstars $27 9-handed: strange BB call by a regular

[SongheJe]

Hello,
I pushed K5 from sb in a situation where EV was positive on all calling ranges.
These days I'm receiving incredible calls by any kind of players. I can't really understand this one.
BB is a regular, +8% ROI on 16000 games.

PokerStars No-Limit Hold'em Tourney, Big Blind is t200 (5 handed) Poker Stars Converter Tool from FlopTurnRiver.com (Format: 2+2 Forums)

BB (t1730)
UTG (t1385)
MP (t7620)
Button (t1345)
Hero (t1420)

Preflop: Hero is SB with 5[img]/images/graemlins/diamond.gif[/img], K[img]/images/graemlins/spade.gif[/img].
<font color="#666666">3 folds</font>, <font color="#CC3333">Hero raises to t1395</font>, BB calls t1195.

Flop: (t2690) T[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>

Turn: (t2690) 4[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>

River: (t2690) 5[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>

Final Pot: t2690

I'm not a maniac, so I really can't understand the call.
He requested time, thinked and did the call with his Jd 7d.