I don't respond to donk bets well

[SossMan]

live rebuy tourney at garden city today. I got moved to this table about 10 min ago and have stole the blinds once, folded the rest, including open folding on the button and SB respectively (had a decent read on the fellow to my left from playing w/ him previously, he snaps a chip on his cards when he plans on playing them after looking at them and holds them in his hands when he doesn't. Both times he had snapped the chip on top and i had garbage, so i figured i would wait).

I have 3600, blinds are 100-200.
Folded to me in the CO and I raise to 600. Folded to BB.

BB had been pretty active and I could tell was very inexperienced. Well, just enough experience to get him in trouble. He had a decent sized stack that he got off one of the good players by calling a pretty big all in overbet w/ A9s saying "it's my favorite hand" and hitting a one card st8 on the river.

So, he calls fairly quickly. Didn't look like he considered raising or folding.

Flop is A [img]/images/graemlins/heart.gif[/img]J [img]/images/graemlins/diamond.gif[/img]6 [img]/images/graemlins/diamond.gif[/img]

he bets out 500 into 1300 pot and I have exactly 3k left.

wtfdid?