Bad Read?

Mel Judah limped UTG and everyone else up to the big blind folded. The flop came out {5-Spades}

and the big blind lead out for 1,000. Judah made it 3,500 with just 3,500 behind, but somehow folded when the big blind moved all-in.

Judah just has 3,500 left and will be making moves very soon...