[Nick C]

When BB donkbets on a board-pairing diamond, it sure does look like BS. Presumably he had something to call on the flop, but it could just be a gutshot or some low PP he'll now get rid of, and trying to take it down on the turn doesn't seem so bad to me, and it helps a little that CO probably doesn't have so much unless he was slowplaying, he hit his flush draw, or he wasn't so sure about his Ax.

And those possibilities for CO add up to enough to make the turn raise hazardous, but there are potential benefits too, so it doesn't seem so bad to me.