Late Tourny exit hand analasis please.

[Tigerscott]

Ultimatebet 20$ 20k guaranteed tourny tonight..
Blinds 200/400 50ante

Late in tourny 174 left out of 1750 peeps top 100 pay...

I'm in BB with K5o
folded to button who calls
sb completes...

Flop K83 rainbow..
sb checks
Believe I bet close to 1k not positive waiting on HH from UB.
Button Folds
SB re raises to 2k..
I decide to push here...
SB calls...
Sb has a stack size of around 9900
I have 10k 100$ more..

Play has been fairly passive at this table and I've sat beside the sb for about 2 hours.. I put him on a King and weak kicker.. I have been fairly tight and only shown strong hands the last two being AA and QQ.. Believe I have a fairly strong table image..

We show hands
I flip K5o
SB shows K6o

turn misses both and a 6 hits river and i'm left 100$ and out next hand in SB..

Great call by him?
Weak play by me?

I really expected him to lay this down.. I believed my push was enough for him to fold not wanting to risk his tourny on top pair weak kicker..I was wrong..

I talked to the guy after and asked why he called with K6.
His response "Because you was in BB!"

Am I way out to lunch and played this horribly or did I just get unlucky and run into the wrong guy at the wrong time...?