Infield fly rule, sorta

[rmein]

Line-drive to the SS w/ runners on first and second and one out. SS appears to attempt to catch the ball but bats it down directly in front of him. Runner on second takes off for third. SS picks it up and steps on second then attempts to get the advancing runner. The runner is safe on a throwing error. Then the batter apparently never advanced first (who knows why). SS then tosses the ball to first for a double play.

Is the infield-fly rule in effect here (on a line drive)or should the DP stand?