Intentionally Dropped Ball or Double Play?

 
With one out and a runner at first base (R1), the batter (B1) hits an easily catchable pop-up toward the 2nd baseman. The 2nd baseman camps under the ball, but he senses that R1 is staying close to first base, so the 2nd baseman intentionally lets the ball drop to the ground (untouched) in front of him. He picks up the ball and throws to first base where the 1st baseman easily tags R1 and then tags first base just before B1 arrives. 
 
The defense believes this is an inning-ending double play, while the offense thinks that there should be a penalty for an intentionally dropped ball.
 
What does the umpire do now?
 
Call
Despite the apparent intention or appearance that a batted ball was intentionally dropped, if a batted ball lands untouched, it is not penalized as an intentionally dropped ball (NF 8-4-1c). In the situation below, the ball was not intentionally dropped, so R1 is out on the tag and B1 is forced out at 1st base -- double play and inning over!